Experiment to conduct state tomography.
cirq.experiments.StateTomographyExperiment(
qubits: Sequence['cirq.Qid'],
prerotations: Optional[Sequence[Tuple[float, float]]] = None
)
Generates data collection protocol for the state tomography experiment.
Does the fitting of generated data to determine the density matrix.
Args |
|---|
qubits
|
Qubits to do the tomography on.
|
prerotations
|
Tuples of (phase_exponent, exponent) parameters for
gates to apply to the qubits before measurement. The actual
rotation applied will be cirq.PhasedXPowGate with the
specified values of phase_exponent and exponent. If None,
we use [(0, 0), (0, 0.5), (0.5, 0.5)], which corresponds
to rotation gates [I, X0.5, Y0.5].
|
Attributes |
|---|
rot_circuit
|
Circuit with parameterized rotation gates to do before the
final measurements.
|
rot_sweep
|
The list of rotations on the qubits to perform before
measurement.
|
mat
|
Matrix of coefficients for the system. Each row is one equation
corresponding to a rotation sequence and bit string outcome for
that rotation sequence. Each column corresponds to the coefficient
on one term in the density matrix.
|
num_qubits
|
Number of qubits to do tomography on.
|
Methods
fit_density_matrix
View source
fit_density_matrix(
counts: np.ndarray
) -> cirq.experiments.TomographyResult
Solves equation mat * rho = probs.
| Args |
|---|
counts
|
A 2D array where each row contains measured counts
of all n-qubit bitstrings for the corresponding pre-rotations
in rot_sweep. The order of the probabilities corresponds to
to rot_sweep and the order of the bit strings corresponds to
increasing integers up to 2**(num_qubits)-1.
|
| Returns |
|---|
TomographyResult with density matrix corresponding to solution of
this system.
|
View source on GitHub