bloqade.pyqrack.device.QuantumState

← Module overview

classQuantumState¶source

bloqade.pyqrack.device.QuantumState

Bases: NamedTuple

A representation of a quantum state as a density matrix, where the density matrix is rho = sum_i eigenvalues[i] |eigenvectors[:,i]><eigenvectors[:,i]|.

class QuantumState

This representation is efficient for low-rank density matrices by only storing the non-zero eigenvalues and corresponding eigenvectors of the density matrix. For example, a pure state has only one non-zero eigenvalue equal to 1.0.

Endianness and qubit ordering of the state vector is consistent with Cirq, where eigenvectors[0,0] corresponds to the amplitude of the |00..000> element of the zeroth eigenvector; eigenvectors[1,0] corresponds to the amplitude of the |00..001> element of the zeroth eigenvector; eigenvectors[3,0] corresponds to the amplitude of the |00..011> element of the zeroth eigenvector; eigenvectors[-1,0] corresponds to the amplitude of the |11..111> element of the zeroth eigenvector. A flip of the LAST bit |00..000><00..001| corresponds to applying a PauliX gate to the FIRST qubit. A flip of the FIRST bit |00..000><10..000| corresponds to applying a PauliX gate to the LAST qubit.

Methods: Not Implemented, pending https://github.com/QuEraComputing/bloqade-circuit/issues/447

Attributes

Name	Type	Description
eigenvalues	1d np.ndarray	The non-zero eigenvalues of the density matrix.
eigenvectors	2d np.ndarray	The corresponding eigenvectors of the density matrix, where eigenvectors[:,i] is the i-th eigenvector.

methodcanonicalize¶source

bloqade.pyqrack.device.QuantumState.canonicalize

def canonicalize(tol: float = 1e-12) -> QuantumState

Parameters

Name	Type	Default	Description
tol	float	1e-12

Returns

QuantumState

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propertydense¶source

bloqade.pyqrack.device.QuantumState.dense

dense: np.ndarray[tuple[int, int], np.complexfloating]

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methodexpect¶source

bloqade.pyqrack.device.QuantumState.expect

def expect(operator: Any) -> float

Parameters

Name	Type	Description
operator	Any

Returns

float

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methodprobability¶source

bloqade.pyqrack.device.QuantumState.probability

def probability() -> np.ndarray[tuple[int], np.floating]

Returns

np.ndarray[tuple[int], np.floating]

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methodvon_neumann_entropy¶source

bloqade.pyqrack.device.QuantumState.von_neumann_entropy

def von_neumann_entropy() -> float

Returns

float

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propertyqubit_basis¶source

bloqade.pyqrack.device.QuantumState.qubit_basis

qubit_basis: list[PyQrackQubit]

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methodreduced_density_matrix¶source

bloqade.pyqrack.device.QuantumState.reduced_density_matrix

Signature

def reduced_density_matrix(qubits: list[PyQrackQubit], tol: float = 1e-12) -> QuantumState

Parameters

Name	Type	Default	Description
qubits	list[PyQrackQubit]	required
tol	float	1e-12

Returns

QuantumState

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methodoverlap¶source

bloqade.pyqrack.device.QuantumState.overlap

def overlap(other: QuantumState) -> complex

Parameters

Name	Type	Description
other	QuantumState

Returns

complex

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