# cirq.experiments.single_qubit_state_tomography¶

cirq.experiments.single_qubit_state_tomography(sampler: cirq.work.sampler.Sampler, qubit: cirq.devices.grid_qubit.GridQubit, circuit: cirq.circuits.circuit.Circuit, repetitions: int = 1000) → cirq.experiments.qubit_characterizations.TomographyResult[source]

Single-qubit state tomography.

The density matrix of the output state of a circuit is measured by first
doing projective measurements in the z-basis, which determine the
diagonal elements of the matrix. A X/2 or Y/2 rotation is then added before
the z-basis measurement, which determines the imaginary and real parts of
the off-diagonal matrix elements, respectively.

See Vandersypen and Chuang, Rev. Mod. Phys. 76, 1037 for details.

Parameters
• sampler – The quantum engine or simulator to run the circuits.

• qubit – The qubit under test.

• circuit – The circuit to execute on the qubit before tomography.

• repetitions – The number of measurements for each basis rotation.

Returns

A TomographyResult object that stores and plots the density matrix.