StabilizerState

class StabilizerState(data, validate=True)

Bases: qiskit.quantum_info.states.quantum_state.QuantumState

StabilizerState class. Stabilizer simulator using the convention from reference [1]. Based on the internal class Clifford.

from qiskit import QuantumCircuit
from qiskit.quantum_info import StabilizerState, Pauli

# Bell state generation circuit
qc = QuantumCircuit(2)
qc.h(0)
qc.cx(0, 1)
stab = StabilizerState(qc)

# Print the StabilizerState
print(stab)

# Calculate the StabilizerState measurement probabilities dictionary
print (stab.probabilities_dict())

# Calculate expectation value of the StabilizerState
print (stab.expectation_value(Pauli('ZZ')))

StabilizerState(StabilizerTable: ['+XX', '+ZZ'])
{'00': 0.5, '11': 0.5}
1

References

1. S. Aaronson, D. Gottesman, Improved Simulation of Stabilizer Circuits, Phys. Rev. A 70, 052328 (2004). arXiv:quant-ph/0406196

Initialize a StabilizerState object.

Parameters

• (StabilizerState or Clifford or Pauli or QuantumCircuit or (data) – qiskit.circuit.Instruction): Data from which the stabilizer state can be constructed.

• validate (boolean) – validate that the stabilizer state data is a valid Clifford.

Methods

conjugate	Return the conjugate of the operator.
copy	Make a copy of current operator.
dims	Return tuple of input dimension for specified subsystems.
evolve	Evolve a stabilizer state by a Clifford operator.
expand	Return the tensor product stabilzier state other ⊗ self.
expectation_value	Compute the expectation value of an operator.
is_valid	Return True if a valid StabilizerState.
measure	Measure subsystems and return outcome and post-measure state.
probabilities	Return the subsystem measurement probability vector.
probabilities_dict	Return the subsystem measurement probability dictionary.
purity	Return the purity of the quantum state, which equals to 1, since it is always a pure state.
reset	Reset state or subsystems to the 0-state.
sample_counts	Sample a dict of qubit measurement outcomes in the computational basis.
sample_memory	Sample a list of qubit measurement outcomes in the computational basis.
seed	Set the seed for the quantum state RNG.
tensor	Return the tensor product stabilzier state self ⊗ other.
to_operator	Convert state to matrix operator class
trace	Return the trace of the stabilizer state as a density matrix, which equals to 1, since it is always a pure state.

Attributes

clifford

Return StabilizerState Clifford data

dim

Return total state dimension.

num_qubits

Return the number of qubits if a N-qubit state or None otherwise.