To't Hauptinholt springen

Vörut-Techniken för QAOA

Schätzte Bruuktieds: 3 Minuten op'n Heron-r2-Prozessor (ANMEERKING: Dat is blots en Schättwert. Diene Lauftied kann anners ween.)

Achtergrund

Düt Notebook stellt vörut Techniken vör, üm de Leistung vun'n Quantum Approximate Optimization Algorithm (QAOA) mit en groot Tahl vun Qubits to verbätern. En Inföhrung in QAOA finnst du in't Tutorial Utilitäts-skalige Quantenoptimeerungsproblemen lösen.

De vörut Techniken in düssem Notebook sünd:

  • SWAP-Strategie mit SAT-Anfangs-Afbillen: Dat is en speziell entwickelt Transpiler-Pass för QAOA, de en SWAP-Strategie un en SAT-Solver tosamen bruukt, üm en betere Utwahl vun physikalischen Qubits op den QPU to maken. De SWAP-Strategie nutzt de Kommutativität vun de QAOA-Operatoren, üm Gaten ümtosorteer, so dat SWAP-Schichten gliektiedig utföhrt warrn kunnen, wat de Deepte vun'n Schaltkreis verringert [1]. Den SAT-Solver bruukt man, üm en Anfangs-Afbillen to finnen, dat de Tahl vun nötigen SWAP-Operatschonen verringert, üm de Qubits in'n Schaltkreis op de physikalischen Qubits vun'n Gerät aftobildden [2].
  • CVaR-Kostenfunkschoon: Normaleerwies bruukt man den Erwartungswert vun'n Kosten-Hamiltonian as Kostenfunkschoon för QAOA, awer as in [3] wiest wurrn is, kann dat Konzentreeren op den Swanz vun de Verdeellung statt op den Erwartungswert de Leistung vun QAOA för kombinatorische Optimeerungsproblemen verbätern. Den CVaR deit genau dat. För en geeven Sett Shots mit entsprekenden Zielweerten vun't betrachtet Optimeerungsproblem is de Conditional Value at Risk (CVaR) mit Konfidenznievo α[0,1]\alpha \in [0, 1] definiert as de Gemiddel vun de α\alpha besten Shots [3]. Dormit entspricht α=1\alpha = 1 den standardmäßigen Erwartungswert, wohingegen α=0\alpha=0 den Mindestwert vun de geevenen Shots entspricht un α(0,1)\alpha \in (0, 1) en Kompromiss is twischen dat Konzentreeren op betere Shots un en gewisse Mittelweertbildung, üm de Optimeerungslandschaft to glöden. Tosweten kann de CVaR as Fehlerminnerungstechnik bruukt warrn, üm de Qualität vun de Zielweert-Schätzen to verbätern [4].

Vörutotsettungen

Vör düssem Tutorial, stell seker, dat du dat Follgendes installeert hest:

  • Qiskit SDK v2.0 oder neeger, mit Visualiseerung-Ünnerstüttung
  • Qiskit Runtime v0.43 oder neeger (pip install qiskit-ibm-runtime)
  • Rustworkx-Graphbibliothek (pip install rustworkx)
  • Python SAT (pip install python-sat)

Instellen

# Added by doQumentation — installs packages not in the Binder environment
!pip install -q python-sat
from __future__ import annotations

import numpy as np
import rustworkx as rx
from dataclasses import dataclass
from itertools import combinations
from threading import Timer
from collections.abc import Callable, Iterable
from pysat.formula import CNF, IDPool
from pysat.solvers import Solver
from scipy.optimize import minimize
from rustworkx.visualization import mpl_draw as draw_graph

from qiskit.quantum_info import SparsePauliOp
from qiskit.circuit.library import QAOAAnsatz
from qiskit.circuit import QuantumCircuit, ParameterVector
from qiskit.transpiler import CouplingMap, PassManager
from qiskit.transpiler.preset_passmanagers import generate_preset_pass_manager
from qiskit.transpiler.passes.routing.commuting_2q_gate_routing import (
SwapStrategy,
FindCommutingPauliEvolutions,
Commuting2qGateRouter,
)

from qiskit_ibm_runtime import QiskitRuntimeService, Session
from qiskit_ibm_runtime import SamplerV2 as Sampler

Max-Cut-Problem

Lat uns kieken, wo wi dat Max-Cut-Problem op'n Graph mit 100 Knoten mit QAOA lösen kunnen. Dat Max-Cut-Problem is en kombinatorisches Optimeerungsproblem, dat op'n Graph G=(V,E)G = (V, E) definiert is, wo VV de Sett vun Knoten un EE de Sett vun Kanten is. De Tschüül is, de Knoten in twee Setten, SS un VSV \setminus S, to verdelen, so dat de Tahl vun Kanten twischen de twee Setten maximeert wart. In düssem Bispeel bruukt wi en Graph mit 100 Knoten, de op en Hardware-Kopplungskarte basiert.

Schritt 1: Klassische Ingaven op en Quantenproblem afbilden

Graph → Hamiltonian

Eerst bildst du dat Problem op'n Quantenschaltkreis af, de för QAOA passt. Details to düssem Vörgang finnst du in't QAOA-Inföhrungs-Tutorial.

# Instantiate runtime to access backend
service = QiskitRuntimeService()
backend = service.least_busy(
min_num_qubits=100, operational=True, simulator=False
)
print(backend)
<IBMBackend('ibm_fez')>
backend.coupling_map.is_symmetric
True
n = 100
graph_100 = rx.PyGraph()
graph_100.add_nodes_from((np.arange(0, n, 1)))
w = 1.0
elist = []

for edge in backend.coupling_map:
if (edge[0] < n) and (edge[1] < n):
if (edge[1], edge[0], w) not in elist:
elist.append((edge[0], edge[1], w))

graph_100.add_edges_from(elist)
draw_graph(graph_100, with_labels=True)

Output of the previous code cell

# Construct cost hamiltonian

def build_max_cut_paulis(graph: rx.PyGraph) -> list[tuple[str, float]]:
"""Convert the graph to Pauli list.

This function does the inverse of `build_max_cut_graph`
"""
pauli_list = []
for edge in list(graph.edge_list()):
paulis = ["I"] * len(graph)
paulis[edge[0]], paulis[edge[1]] = "Z", "Z"

weight = graph.get_edge_data(edge[0], edge[1])

pauli_list.append(("".join(paulis)[::-1], weight))

return pauli_list

max_cut_paulis = build_max_cut_paulis(graph_100)

cost_hamiltonian = SparsePauliOp.from_list(max_cut_paulis)
print("Cost Function Hamiltonian:", cost_hamiltonian)
Cost Function Hamiltonian: SparsePauliOp(['IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZ', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZI', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIZIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIZIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIZIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIZIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIZIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIZIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIZIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIZIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IZIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'ZIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII'],
coeffs=[1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j])

Schritt 2: Problem för de Quantenhardware-Utföhrung optimeren

SWAP-Strategie mit'n SAT-Anfangs-Afbillen

Wi wiest, wo man QAOA-Schaltkresen mit de SWAP-Strategie un dat SAT-Anfangs-Afbillen buen un optimeren kann — en speziell entwickelt Transpiler-Pass för QAOA, de op quadratische Probleme tosneden is.

In düssem Bispeel wählt wi en SWAP-Inföhr-Strategie för Blöcke vun kommutierenden Twee-Qubit-Gaten, de Schichten vun SWAP-Gaten anwendet, de gliektiedig op de Kopplungskarte utföhrt warrn kunnen. Düsse Strategie wart in [1] vörstellt un wart in Commuting2qGateRouter inföhrt, de as standardiseerter Qiskit-Transpiler-Pass torverfügung steiht (süh Commuting2qGateRouter). Wi bruukt in düssem Bispeel en Linien-SWAP-Strategie.

# Extract longest path with no repeated nodes
nodes = rx.longest_simple_path(graph_100)

# Collect even edges and odd edges
even_edges = [
(nodes[i], nodes[i + 1])
if nodes[i] < nodes[i + 1]
else (nodes[i + 1], nodes[i])
for i in range(0, len(nodes) - 1, 2)
]
odd_edges = [
(nodes[i], nodes[i + 1])
if nodes[i] < nodes[i + 1]
else (nodes[i + 1], nodes[i])
for i in range(1, len(nodes) - 1, 2)
]
edge_list = [
(edge[0], edge[1]) if edge[0] < edge[1] else (edge[1], edge[0])
for edge in graph_100.edge_list()
]

swap_strategy = SwapStrategy(CouplingMap(edge_list), (even_edges, odd_edges))

Den Graph mit'n SAT-Mapper ümafbilden

Uk wenn en Schaltkreis ut kommutierende Gaten besteiht (dat is bi'n QAOA-Schaltkreis so, awer ook bi Trotterisierten Simulatschonen vun Ising-Hamiltonians), is dat Finnen vun en gode Anfangs-Afbillen en swore Opgave. De SAT-baseerde Ansatz ut [2] maakt dat Finnen vun effektive Anfangs-Afbillens för Schaltkresen mit kommutierenden Gaten mööglich, wat to en bedütsame Verringerung vun de Tahl vun nötigen SWAP-Schichten föhrt. Düsse Ansatz is demonstreert wurrn, dat he op bit to 500 Qubits skalert, as in'n Paper wiest wurrn is.

De follgendes Code wiest, wo man den SATMapper vun Matsuo et al. bruukt, üm den Graph ümtomappen. Düss Vörgang erlöövt, dat Problem op en optimalere Anfangstostand för en angeefte SWAP-Strategie aftobildden, wat to en bedütsame Verringerung vun de Tahl vun nötigen SWAP-Schichten föhrt.

In SATMapper is dat Problem, en godes Anfangs-Afbillen to finnen, as SAT-Problem formulert. En SAT-Solver bruukt man, üm sülk en Anfangs-Afbillen för den QAOA-Schaltkreis to finnen. python-sat (kurz pysat) is en Python-Bibliothek för en SAT-Solver, de wi in düssem Bispeel bruukt.

"""A class to solve the SWAP gate insertion initial mapping problem
using the SAT approach from https://arxiv.org/abs/2212.05666.
"""

@dataclass
class SATResult:
"""A data class to hold the result of a SAT solver."""

satisfiable: bool # Satisfiable is True if the SAT model could be solved
# in a given time.
solution: dict # The solution to the SAT problem if it is satisfiable.
mapping: list # The mapping of nodes in the pattern graph to nodes in the
# target graph.
elapsed_time: float # The time it took to solve the SAT model.

class SATMapper:
r"""A class to introduce a SAT-approach to solve
the initial mapping problem in SWAP gate insertion for commuting gates.

When this pass is run on a DAG it will look for the first instance of
:class:`.Commuting2qBlock` and use the program graph :math:`P` of this block
of gates to find a layout for a given swap strategy. This layout is found
with a binary search over the layers :math:`l` of the swap strategy. At each
considered layer a subgraph isomorphism problem formulated as a SAT is solved
by a SAT solver. Each instance is whether it is possible to embed the program
graph :math:`P` into the effective connectivity graph :math:`C_l` that is
achieved by applying :math:`l` layers of the swap strategy to the coupling map
:math:`C_0` of the backend. Since solving SAT problems can be hard, a
``time_out`` fixes the maximum time allotted to the SAT solver for each
instance. If this time is exceeded the considered problem is deemed
unsatisfiable and the binary search proceeds to the next number of swap
layers :math:``l``.
"""

def __init__(self, timeout: int = 60):
"""Initialize the SATMapping.

Args:
timeout: The allowed time in seconds for each iteration of the SAT
solver. This variable defaults to 60 seconds.
"""
self.timeout = timeout

def find_initial_mappings(
self,
program_graph: rx.Graph,
swap_strategy: SwapStrategy,
min_layers: int | None = None,
max_layers: int | None = None,
) -> dict[int, SATResult]:
r"""Find an initial mapping for a given swap strategy. Perform a
binary search over the number of swap layers, and for each number
of swap layers solve a subgraph isomorphism problem formulated as
a SAT problem.

Args:
program_graph (rx.Graph): The program graph with commuting gates, where
each edge represents a two-qubit gate.
swap_strategy (SwapStrategy): The swap strategy to use to find the
initial mapping.
min_layers (int): The minimum number of swap layers to consider.
Defaults to the maximum degree of the
program graph - 2.
max_layers (int): The maximum number of swap layers to consider.
Defaults to the number of qubits in the
swap strategy - 2.

Returns:
dict[int, SATResult]: A dictionary containing the results of the SAT
solver for each number of swap layers.
"""
num_nodes_g1 = len(program_graph.nodes())
num_nodes_g2 = swap_strategy.distance_matrix.shape[0]
if num_nodes_g1 > num_nodes_g2:
return SATResult(False, [], [], 0)
if min_layers is None:
# use the maximum degree of the program graph - 2
# as the lower bound.
min_layers = max((d for _, d in program_graph.degree)) - 2
if max_layers is None:
max_layers = num_nodes_g2 - 1

variable_pool = IDPool(start_from=1)
variables = np.array(
[
[variable_pool.id(f"v_{i}_{j}") for j in range(num_nodes_g2)]
for i in range(num_nodes_g1)
],
dtype=int,
)
vid2mapping = {v: idx for idx, v in np.ndenumerate(variables)}
binary_search_results = {}

def interrupt(solver):
# This function is called to interrupt the solver when the
# timeout is reached.
solver.interrupt()

# Make a cnf (conjunctive normal form) for the one-to-one
# mapping constraint
cnf1 = []
for i in range(num_nodes_g1):
clause = variables[i, :].tolist()
cnf1.append(clause)
for k, m in combinations(clause, 2):
cnf1.append([-1 * k, -1 * m])
for j in range(num_nodes_g2):
clause = variables[:, j].tolist()
for k, m in combinations(clause, 2):
cnf1.append([-1 * k, -1 * m])

# Perform a binary search over the number of swap layers to find the
# minimum number of swap layers that satisfies the subgraph isomorphism
# problem.
while min_layers < max_layers:
num_layers = (min_layers + max_layers) // 2

# Create the connectivity matrix. Note that if the swap strategy
# cannot reach full connectivity then its distance matrix will have
# entries with -1. These entries must be treated as False.
d_matrix = swap_strategy.distance_matrix
connectivity_matrix = (
(-1 < d_matrix) & (d_matrix <= num_layers)
).astype(int)
# Make a cnf for the adjacency constraint
cnf2 = []
for e_0, e_1 in list(program_graph.edge_list()):
clause_matrix = np.multiply(
connectivity_matrix, variables[e_1, :]
)
clause = np.concatenate(
(
[[-variables[e_0, i]] for i in range(num_nodes_g2)],
clause_matrix,
),
axis=1,
)
# Remove 0s from each clause
cnf2.extend([c[c != 0].tolist() for c in clause])

cnf = CNF(from_clauses=cnf1 + cnf2)

with Solver(bootstrap_with=cnf, use_timer=True) as solver:
# Solve the SAT problem with a timeout.
# Timer is used to interrupt the solver when the
# timeout is reached.
timer = Timer(self.timeout, interrupt, [solver])
timer.start()
status = solver.solve_limited(expect_interrupt=True)
timer.cancel()
# Get the solution and the elapsed time.
sol = solver.get_model()
e_time = solver.time()

print(
f"Layers: {num_layers}, Status: {status}, Time: {e_time}"
)
if status:
# If the SAT problem is satisfiable, convert the solution
# to a mapping.
mapping = [vid2mapping[idx] for idx in sol if idx > 0]
binary_search_results[num_layers] = SATResult(
status, sol, mapping, e_time
)
max_layers = num_layers
else:
# If the SAT problem is unsatisfiable, return the last
# satisfiable solution.
binary_search_results[num_layers] = SATResult(
status, sol, [], e_time
)
min_layers = num_layers + 1

return binary_search_results

def remap_graph_with_sat(
self, graph: rx.Graph, swap_strategy, max_layers
):
"""Applies the SAT mapping.

Args:
graph (nx.Graph): The graph to remap.
swap_strategy (SwapStrategy): The swap strategy to use
to find the initial mapping.

Returns:
tuple: A tuple containing the remapped graph, the edge map, and the
number of layers of the swap strategy that was used to find the
initial mapping. If no solution is found then the tuple contains
None for each element. Note the returned edge map `{k: v}` means that
node `k` in the original graph gets mapped to node `v` in the
Pauli strings.
"""
num_nodes = len(graph.nodes())
results = self.find_initial_mappings(
graph, swap_strategy, 0, max_layers
)
solutions = [k for k, v in results.items() if v.satisfiable]

if len(solutions):
min_k = min(solutions)
edge_map = dict(results[min_k].mapping)
# Create the remapped graph
remapped_graph = rx.PyGraph()
remapped_graph.add_nodes_from(range(num_nodes))
mapping = dict(results[min_k].mapping)
for i, graph_edge in enumerate(list(graph.edge_list())):
remapped_edge = tuple(mapping[node] for node in graph_edge)
remapped_graph.add_edge(*remapped_edge, graph.edges()[i])
return remapped_graph, edge_map, min_k
else:
return None, None, None
sm = SATMapper(timeout=10)
remapped_graph, edge_map, min_swap_layers = sm.remap_graph_with_sat(
graph=graph_100, swap_strategy=swap_strategy, max_layers=1
)
print("Map from old to new nodes: ", edge_map)
print("Min SWAP layers:", min_swap_layers)
draw_graph(remapped_graph, node_size=200, with_labels=True, width=1)
Layers: 0, Status: True, Time: 0.022812999999999306
Map from old to new nodes: {0: 0, 1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9, 10: 10, 11: 11, 12: 12, 13: 13, 14: 14, 15: 15, 16: 16, 17: 17, 18: 18, 19: 19, 20: 20, 21: 21, 22: 22, 23: 23, 24: 24, 25: 25, 26: 26, 27: 27, 28: 28, 29: 29, 30: 30, 31: 31, 32: 32, 33: 33, 34: 34, 35: 35, 36: 36, 37: 37, 38: 38, 39: 39, 40: 40, 41: 41, 42: 42, 43: 43, 44: 44, 45: 45, 46: 46, 47: 47, 48: 48, 49: 49, 50: 50, 51: 51, 52: 52, 53: 53, 54: 54, 55: 55, 56: 56, 57: 57, 58: 58, 59: 59, 60: 60, 61: 61, 62: 62, 63: 63, 64: 64, 65: 65, 66: 66, 67: 67, 68: 68, 69: 69, 70: 70, 71: 71, 72: 72, 73: 73, 74: 74, 75: 75, 76: 76, 77: 77, 78: 78, 79: 79, 80: 80, 81: 81, 82: 82, 83: 83, 84: 84, 85: 85, 86: 86, 87: 87, 88: 88, 89: 89, 90: 90, 91: 91, 92: 92, 93: 93, 94: 94, 95: 95, 96: 96, 97: 97, 98: 98, 99: 99}
Min SWAP layers: 0

Output of the previous code cell

remapped_max_cut_paulis = build_max_cut_paulis(remapped_graph)
# define a qiskit SparsePauliOp from the list of paulis
remapped_cost_operator = SparsePauliOp.from_list(remapped_max_cut_paulis)
print(remapped_cost_operator)
SparsePauliOp(['IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZ', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZI', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIZIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIZIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIZIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIZIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIZIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIZIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIZIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIZIIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIZIIIIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIZIIIIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IZIIIIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'IIIIZZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII', 'ZIIIZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII'],
coeffs=[1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j, 1.+0.j,
1.+0.j, 1.+0.j, 1.+0.j])

En QAOA-Schaltkreis mit de SWAP-Strategie un de SAT-Afbillen buuen

Wi wüllt de SWAP-Strategien blots op de Kosten-Operator-Schicht anwenden, dorvun fangen wi dorrmit an, den isolierten Block to maken, den wi later transformeert un an den finalen QAOA-Schaltkreis anhängt.

Dormit können wi de QAOAAnsatz-Klasse vun Qiskit bruuken. Wi geeven en legen Schaltkreis in de Felder initial_state un mixer_operator in, üm seker to stellen, dat wi en isolierten Kosten-Operator-Schicht buuen. Wi definieren ook de Kantenkoloreerungs-Karte, so dat RZZ-Gaten neven SWAP-Gaten plazeert warrn. Düsse strategische Platzeering erlöövt uns, CX-Annulleerngen to nutzen, üm den Schaltkreis för betere Leistung to optimeren. Düss Vörgang wart in de create_qaoa_swap_circuit-Funkschoon utföhrt.

def make_meas_map(circuit: QuantumCircuit) -> dict:
"""Return a mapping from qubit index (the key) to classical bit (the value).

This allows us to account for the swapping order introduced by the SWAP strategy.
"""
creg = circuit.cregs[0]
qreg = circuit.qregs[0]

meas_map = {}
for inst in circuit.data:
if inst.operation.name == "measure":
meas_map[qreg.index(inst.qubits[0])] = creg.index(inst.clbits[0])

return meas_map

def apply_swap_strategy(
circuit: QuantumCircuit,
swap_strategy: SwapStrategy,
edge_coloring: dict[tuple[int, int], int] | None = None,
) -> QuantumCircuit:
"""Transpile with a SWAP strategy.

Returns:
A quantum circuit transpiled with the given swap strategy.
"""

pm_pre = PassManager(
[
FindCommutingPauliEvolutions(),
Commuting2qGateRouter(
swap_strategy,
edge_coloring,
),
]
)
return pm_pre.run(circuit)

def apply_qaoa_layers(
cost_layer: QuantumCircuit,
meas_map: dict,
num_layers: int,
gamma: list[float] | ParameterVector = None,
beta: list[float] | ParameterVector = None,
initial_state: QuantumCircuit = None,
mixer: QuantumCircuit = None,
):
"""Applies QAOA layers to construct circuit.

First, the initial state is applied. If `initial_state` is None, we begin in the
initial superposition state. Next, we alternate between layers of the cost operator
and the mixer. The cost operator is alternatively applied in order and in reverse
instruction order. This allows us to apply the swap strategy on odd `p` layers
and undo the swap strategy on even `p` layers.
"""

num_qubits = cost_layer.num_qubits
new_circuit = QuantumCircuit(num_qubits, num_qubits)

if initial_state is not None:
new_circuit.append(initial_state, range(num_qubits))
else:
# all h state by default
new_circuit.h(range(num_qubits))

if gamma is None or beta is None:
gamma = ParameterVector("γ'", num_layers)
if mixer is None or mixer.num_parameters == 0:
beta = ParameterVector("β'", num_layers)
else:
beta = ParameterVector("β'", num_layers * mixer.num_parameters)

if mixer is not None:
mixer_layer = mixer
else:
mixer_layer = QuantumCircuit(num_qubits)
mixer_layer.rx(-2 * beta[0], range(num_qubits))

for layer in range(num_layers):
bind_dict = {cost_layer.parameters[0]: gamma[layer]}
cost_layer_ = cost_layer.assign_parameters(bind_dict)
bind_dict = {
mixer_layer.parameters[i]: beta[layer + i]
for i in range(mixer_layer.num_parameters)
}
layer_mixer = mixer_layer.assign_parameters(bind_dict)

if layer % 2 == 0:
new_circuit.append(cost_layer_, range(num_qubits))
else:
new_circuit.append(cost_layer_.reverse_ops(), range(num_qubits))

new_circuit.append(layer_mixer, range(num_qubits))

for qidx, cidx in meas_map.items():
new_circuit.measure(qidx, cidx)

return new_circuit

def create_qaoa_swap_circuit(
cost_operator: SparsePauliOp,
swap_strategy: SwapStrategy,
edge_coloring: dict = None,
theta: list[float] = None,
qaoa_layers: int = 1,
initial_state: QuantumCircuit = None,
mixer: QuantumCircuit = None,
):
"""Create the circuit for QAOA.

Notes: This circuit construction for QAOA works for quadratic terms in `Z` and will be
extended to first-order terms in `Z`. Higher-orders are not supported.

Args:
cost_operator: the cost operator.
swap_strategy: selected swap strategy
edge_coloring: A coloring of edges that should correspond to the coupling
map of the hardware. It defines the order in which we apply the Rzz
gates. This allows us to choose an ordering such that `Rzz` gates will
immediately precede SWAP gates to leverage CNOT cancellation.
theta: The QAOA angles.
qaoa_layers: The number of layers of the cost operator and the mixer operator.
initial_state: The initial state on which we apply layers of cost operator
and mixer.
mixer: The QAOA mixer. It will be applied as is onto the QAOA circuit. Therefore,
its output must have the same ordering of qubits as its input.
"""

num_qubits = cost_operator.num_qubits

if theta is not None:
gamma = theta[: len(theta) // 2]
beta = theta[len(theta) // 2 :]
qaoa_layers = len(theta) // 2
else:
gamma = beta = None

# First, create the ansatz of one layer of QAOA without mixer
cost_layer = QAOAAnsatz(
cost_operator,
reps=1,
initial_state=QuantumCircuit(num_qubits),
mixer_operator=QuantumCircuit(num_qubits),
).decompose()

# This will allow us to recover the permutation of the measurements that the swaps introduce.
cost_layer.measure_all()

# Now, apply the swap strategy for commuting gates
cost_layer = apply_swap_strategy(cost_layer, swap_strategy, edge_coloring)

# Compute the measurement map (qubit to classical bit).
# We will apply this for odd layers where the swaps were inserted.
if qaoa_layers % 2 == 1:
meas_map = make_meas_map(cost_layer)
else:
meas_map = {idx: idx for idx in range(num_qubits)}

cost_layer.remove_final_measurements()

# Finally, introduce the mixer circuit and add measurements following measurement map
circuit = apply_qaoa_layers(
cost_layer, meas_map, qaoa_layers, gamma, beta, initial_state, mixer
)

return circuit
# We can define the edge_coloring map so that RZZ gates are positioned right before SWAP gates to exploit CX cancellations
# We use greedy edge coloring from rustworkx to color the edges of the graph. This coloring is used to order the RZZ gates in the circuit.

edge_coloring_idx = rx.graph_greedy_edge_color(graph_100)
edge_coloring = {
edge: edge_coloring_idx[idx]
for idx, edge in enumerate(list(graph_100.edge_list()))
}
edge_coloring = {tuple(sorted(k)): v for k, v in edge_coloring.items()}
qaoa_circ = create_qaoa_swap_circuit(
remapped_cost_operator,
swap_strategy,
edge_coloring=edge_coloring,
qaoa_layers=1,
)
qaoa_circ.draw(output="mpl", fold=False)
/Users/mirko/Workspace/documentation/.venv/lib/python3.13/site-packages/qiskit/circuit/quantumcircuit.py:4625: UserWarning: Trying to add QuantumRegister to a QuantumCircuit having a layout
circ.add_register(qreg)

Output of the previous code cell

Schritt 3: Utföhren mit Qiskit-Primitiven

En CVaR-Kostenfunkschoon definieren

Düt Bispeel wiest, wo man de Conditional Value at Risk (CVaR)-Kostenfunkschoon ut [3] binnen de variationellen Quantenoptimeerungsalgorithmen bruukt.

De CVaR vun en Zufallsvariable XX för en Konfidenznievo α(0,1]α ∈ (0, 1] is definiert as CVaRα(X)=E[XXFX1(α)]CVaR_{\alpha}(X) = \mathbb{E} \lbrack X | X \leq F_X^{-1}(\alpha) \rbrack wo FX1(p)F_X^{-1}(p) de inverse kumulative Verdeelungsfunkschoon vun XX is. Mit annere Wörd: CVaR is den Erwartungswert vun'n unnersten α\alpha-Swanz vun de Verdeellung vun XX.

pass_manager = generate_preset_pass_manager(
backend=backend,
optimization_level=3,
)

transpiled_qaoa_circ = pass_manager.run(qaoa_circ)
# Utility functions for the evaluation of the expectation value of a measured state
# In this code, for optimization, the measured state is converted into a bit string,
# and the sign of the value is determined by taking the exclusive OR of the bits
# corresponding to Pauli Z.

_PARITY = np.array(
[-1 if bin(i).count("1") % 2 else 1 for i in range(256)],
dtype=np.complex128,
)

def evaluate_sparse_pauli(state: int, observable: SparsePauliOp) -> complex:
"""Utility for the evaluation of the expectation value of a measured state.

Args:
state (int): The measured state.
observable (SparsePauliOp): The observable to evaluate the expectation value for.

Returns:
complex: The expectation value of the measured state.
"""
packed_uint8 = np.packbits(
observable.paulis.z, axis=1, bitorder="little"
) # convert observable to array with 8 bit integer
state_bytes = np.frombuffer(
state.to_bytes(packed_uint8.shape[1], "little"),
dtype=np.uint8, # convert bitstring to array with 8 bit integer
)
reduced = np.bitwise_xor.reduce(
packed_uint8 & state_bytes, axis=1
) # take bitwise xor of the result of 'and' conditional on the above two, return 0 or 1
return np.sum(observable.coeffs * _PARITY[reduced])
def qaoa_sampler_cost_fun(
params, ansatz, hamiltonian, sampler, aggregation=None
):
"""Standard sampler-based QAOA cost function to be plugged into optimizer routines.

Args:
params (np.ndarray): Parameters for the ansatz.
ansatz (QuantumCircuit): Ansatz circuit.
hamiltonian (SparsePauliOp): Hamiltonian to be minimized.
sampler (QAOASampler): Sampler to be used.
aggregation (Callable | float | None): Aggregation function to be applied to
the sampled results. If None, the sum of the expectation values is returned.
If float, the CVaR with the given alpha is used.
"""
# Run the circuit
job = sampler.run([(ansatz, params)])
sampler_result = job.result()
sampled_int_counts = sampler_result[
0
].data.c.get_int_counts() # bitstrings are stored as integers
shots = sum(sampled_int_counts.values())
int_count_distribution = {
key: val / shots for key, val in sampled_int_counts.items()
}

# a dictionary containing: {state: (measurement probability, value)}
evaluated = {
state: (
probability,
np.real(evaluate_sparse_pauli(state, hamiltonian)),
)
for state, probability in int_count_distribution.items()
}

# If aggregation is None, return the sum of the expectation values.
# If aggregation is a float, return the CVaR with the given alpha.
# Otherwise, use the aggregation function.
if aggregation is None:
result = sum(
probability * value for probability, value in evaluated.values()
)
elif isinstance(aggregation, float):
cvar_aggregation = _get_cvar_aggregation(aggregation)
result = cvar_aggregation(evaluated.values())
else:
result = aggregation(evaluated.values())

global iter_counts, result_dict
iter_counts += 1
temp_dict = {}
temp_dict["params"] = params.tolist()
temp_dict["cvar_fval"] = result
temp_dict["fval"] = sum(
probability * value for probability, value in evaluated.values()
)
temp_dict["distribution"] = sampled_int_counts
temp_dict["evaluated"] = evaluated
result_dict[iter_counts] = temp_dict
print(f"Iteration {iter_counts}: {result}")

return result

def _get_cvar_aggregation(alpha: float | None) -> Callable:
"""Return the CVaR aggregation function with the given alpha.

Args:
alpha (float | None): Alpha value for the CVaR aggregation. If None, 1 is used
by default.
Raises:
ValueError: If alpha is not in [0, 1].
"""
if alpha is None:
alpha = 1
elif not 0 <= alpha <= 1:
raise ValueError(f"alpha must be in [0, 1], but {alpha} was given.")

def cvar_aggregation(
objective_dict: Iterable[tuple[float, float]],
) -> float:
"""Return the CVaR of the given measurements.
Args:
objective_dict (Iterable[tuple[float, float]]): An iterable of tuples containing
the measured bit string and the objective value based on the bit string.

"""
sorted_measurements = sorted(objective_dict, key=lambda x: x[1])
# accumulate the probabilities until alpha is reached
accumulated_percent = 0.0
cvar = 0.0
for probability, value in sorted_measurements:
cvar += value * min(probability, alpha - accumulated_percent)
accumulated_percent += probability
if accumulated_percent >= alpha:
break
return cvar / alpha

return cvar_aggregation

De CVaR kann as Fehlerminnerungstechnik bruukt warrn, as vörher diskuteert [4]. In düssem Bispeel bestimmt wi α\alpha un de Tahl vun Shots na de Fehlerrate vun'n Schaltkreis.

num_2q_ops = transpiled_qaoa_circ.count_ops()[
"cz"
] # the two qubit gates on our backend are cz's.

for el in backend.properties().general:
if el.name[:2] == "lf" and el.name[3:] == str(
n
): # pick out lf_100, lf of the best 100q chain
lf = el.value # layer fidelity
print("layer fidelity", lf)
eplg = 1 - lf ** (1 / (n - 1)) # error per layered gate (EPLG)
fid_cz = 1 - eplg
gamma_cz = 1 / fid_cz**2
gamma_circ = gamma_cz**num_2q_ops

cvar_aggregation = 1 / np.sqrt(gamma_circ)
print("")
print("The corresponding CVaR aggregation value is: ", cvar_aggregation)
print(
"To mitigate the twirled noise, increase shots by a factor of",
np.sqrt(gamma_circ),
)
layer fidelity 0.5454643821399414

The corresponding CVaR aggregation value is: 0.2568730767702702
To mitigate the twirled noise, increase shots by a factor of 3.8929731857197782
iter_counts = 0
result_dict = {}
init_params = [np.pi, np.pi / 2]

with Session(backend=backend) as session:
sampler = Sampler(mode=session)
sampler.options.default_shots = int(1000 / cvar_aggregation)
sampler.options.dynamical_decoupling.enable = True
sampler.options.dynamical_decoupling.sequence_type = "XY4"
sampler.options.twirling.enable_gates = True
sampler.options.twirling.enable_measure = True

result = minimize(
qaoa_sampler_cost_fun,
init_params,
args=(
transpiled_qaoa_circ,
remapped_cost_operator,
sampler,
cvar_aggregation,
),
method="COBYLA",
tol=1e-2,
)
print(result)
Iteration 1: -13.227556797094595
Iteration 2: -13.181545294899571
Iteration 3: -13.149537293372594
Iteration 4: -3.305576300816324
Iteration 5: -12.647411769418035
Iteration 6: -13.443610807401718
Iteration 7: -12.475368761210511
Iteration 8: -15.905726329447413
Iteration 9: -18.011752834505565
Iteration 10: -14.125781339945583
Iteration 11: -19.693673319331744
Iteration 12: -21.175543794613695
Iteration 13: -21.805701324676196
Iteration 14: -22.121280244318488
Iteration 15: -20.02575633517435
Iteration 16: -22.399349757584158
Iteration 17: -22.569392265696226
Iteration 18: -21.877719328111898
Iteration 19: -22.79144777628963
Iteration 20: -22.437359259397432
Iteration 21: -23.021505287264777
Iteration 22: -22.69742427180412
Iteration 23: -23.12553129222746
Iteration 24: -22.893473281156922
message: Return from COBYLA because the trust region radius reaches its lower bound.
success: True
status: 0
fun: -23.12553129222746
x: [ 2.766e+00 1.080e+00]
nfev: 24
maxcv: 0.0

Schritt 4: Nohbearbeidung un Rückgaav vun't Resultat in gewünschten klassischen Format

from matplotlib import pyplot as plt

plt.figure(figsize=(12, 6))
plt.plot(
[result_dict[i]["cvar_fval"] for i in range(1, iter_counts + 1)],
label="CVaR",
)
plt.plot(
[result_dict[i]["fval"] for i in range(1, iter_counts + 1)],
label="Standard",
)
plt.legend()
plt.xlabel("Iteration")
plt.ylabel("Cost")
plt.show()

Output of the previous code cell

De Follgendes holt de beste Lösung ut de sampleten Bitfolgen rut

# sort the result_dict[iter_counts]['evaluated'] by the CVaR value
sorted_result_dict = [
(k, v)
for k, v in sorted(
result_dict[iter_counts]["evaluated"].items(),
key=lambda item: item[1][1],
)
]
print(
f"bitstring (int): {sorted_result_dict[0][0]}, probability: {sorted_result_dict[0][1][0]}, objective value: {sorted_result_dict[0][1][1]}"
)
bitstring (int): 283561207335785714592526814041, probability: 0.00025693730729701953, objective value: -43.0

Betrachte den Hamiltonian HCH_C för dat Max-Cut-Problem. Lat jeden Knoten vun'n Graph mit en Qubit in'n Tostand 0|0\rangle oder 1|1\rangle verbunnen ween, wo de Wert den Sett angeevt, in den de Knoten is. De Tschüül vun't Problem is, de Tahl vun Kanten (v1,v2)(v_1, v_2) to maximeren, för de gilt v1=0v_1 = |0\rangle un v2=1v_2 = |1\rangle, oder umgekehrt. Wenn wi den ZZ-Operator mit jeden Qubit verknüpft, wo

Z0=0Z1=1 Z|0\rangle = |0\rangle \qquad Z|1\rangle = -|1\rangle

dann hört en Kante (v1,v2)(v_1, v_2) to den Schnitt, wenn de Eigenwert vun (Z1v1)(Z2v2)=1(Z_1|v_1\rangle) \cdot (Z_2|v_2\rangle) = -1 is; mit annere Wörd, de Qubits, de mit v1v_1 un v2v_2 verbunnen sünd, sünd verschieden. Gliekerwies hört (v1,v2)(v_1, v_2) nich to den Schnitt, wenn de Eigenwert vun (Z1v1)(Z2v2)=1(Z_1|v_1\rangle) \cdot (Z_2|v_2\rangle) = 1 is

from typing import Sequence

def to_bitstring(integer, num_bits):
result = np.binary_repr(integer, width=num_bits)
return [int(digit) for digit in result]

def evaluate_sample(x: Sequence[int], graph: rx.PyGraph) -> float:
assert len(x) == len(
list(graph.nodes())
), "The length of x must coincide with the number of nodes in the graph."
return sum(
x[u] * (1 - x[v])
+ x[v]
* (
1 - x[u]
) # x[u] = x[v] if same cut, x[u] \neq x[v] if different cuts
for u, v in list(graph.edge_list())
)

bitstring = to_bitstring(
sorted_result_dict[0][0], len(list(remapped_graph.nodes()))
)
bitstring = bitstring[::-1]
print(f"Result bitstring (binary) : {bitstring}")

cut_value = evaluate_sample(bitstring, remapped_graph)
print(f"The value of the cut is: {cut_value}")
Result bitstring (binary) : [1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0]
The value of the cut is: 77

To'n Afsluss, lat uns en Graph na den CVaR-Resultat teeknen. Wi verdelen de Graphknoten in twee Setten na dat CVaR-Resultat. De Knoten in'n eersten Sett warrn grau koloort, un de Knoten in'n tweeten Sett warrn lila koloort. De Kanten twischen de twee Setten sünd de Kanten, de dörch de Partitioneerung sneden warrn.

def plot_result(G, x):
colors = ["tab:grey" if i == 0 else "tab:purple" for i in x]
pos, _default_axes = rx.spring_layout(G), plt.axes(frameon=True)
rx.visualization.mpl_draw(
G,
node_color=colors,
node_size=150,
alpha=0.8,
pos=pos,
with_labels=True,
width=1,
)

plot_result(graph_100, to_bitstring(sorted_result_dict[0][0], 100)[::-1])

Output of the previous code cell

Referenzen

[1] Weidenfeller, J., Valor, L. C., Gacon, J., Tornow, C., Bello, L., Woerner, S., & Egger, D. J. (2022). Scaling of the quantum approximate optimization algorithm on superconducting qubit based hardware. Quantum, 6, 870.

[2] Matsuo, A., Yamashita, S., & Egger, D. J. (2023). A SAT approach to the initial mapping problem in SWAP gate insertion for commuting gates. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, 106(11), 1424-1431.

[3] Barkoutsos, P. K., Nannicini, G., Robert, A., Tavernelli, I., & Woerner, S. (2020). Improving variational quantum optimization using CVaR. Quantum, 4, 256.

[4] Barron, S. V., Egger, D. J., Pelofske, E., Bärtschi, A., Eidenbenz, S., Lehmkuehler, M., & Woerner, S. (2023). Provable bounds for noise-free expectation values computed from noisy samples. arXiv preprint arXiv:2312.00733.

Tutorial-Ümfrag

Nehm di en Minuut Tiet un gif Feedback to düssem Tutorial. Diene Anmerkungen helpt uns, unse Inhalte un de Bruukererfaarhung to verbätern.

Link to survey