Quantum Shapley Value Toolbox

Experimental Python toolbox for Shapley values with uncertain value functions in general (see Shapley Values with Uncertain Value Functions) and quantum Shapley values in particular (see Explaining Quantum Circuits with Shapley Values: Towards Explainable Quantum Machine Learning). Quantum Shapley values provide a method to measure the influence of gates within quantum circuit with respect to a freely customizable value function, for example expressibility or entanglement capability.

Usage

For quantum Shapley values, the toolbox presumes a representation of quantum circuits via Qiskit.

Minimal working example:

from qiskit import Aer
from qiskit.utils import QuantumInstance
from qiskit.circuit.library import QAOAAnsatz
from qiskit.opflow import PauliSumOp
from qshap import QuantumShapleyValues
from qvalues import value_H
from tools import visualize_shapleys

# define circuit
H = PauliSumOp.from_list([('ZZI', 1), ('ZII', 2), ('ZIZ', -3)])
qc = QAOAAnsatz(cost_operator=H, reps=1)
qc = qc.decompose().decompose().decompose()
qc = qc.assign_parameters([0]*len(qc.parameters))

# define quantum instance
quantum_instance = QuantumInstance(backend=Aer.get_backend('statevector_simulator'))

# setup quantum Shapley values
qsv = QuantumShapleyValues(qc, value_fun=value_H, value_kwargs_dict=dict(H=H), quantum_instance=quantum_instance)
print(qsv)

# evaluate quantum Shapley values
qsv()

# show results
print(qsv.phi_dict)
visualize_shapleys(qc, phi_dict=qsv.phi_dict).draw()

As a result, the quantum Shapley values assigned to each gate are plotted:

📖 Citation

If you find this code useful in your research, please consider citing Explaining Quantum Circuits with Shapley Values: Towards Explainable Quantum Machine Learning:

@misc{heese2023explaining,
  title={Explaining Quantum Circuits with Shapley Values: Towards Explainable Quantum Machine Learning}, 
  author={Raoul Heese and Thore Gerlach and Sascha Mücke and Sabine Müller and Matthias Jakobs and Nico Piatkowski},
  year={2023},
  eprint={2301.09138},
  archivePrefix={arXiv},
  primaryClass={quant-ph}
  }

This project is currently not under development and is not actively maintained.