qat.analog.tomography.compute_density_matrix

qat.analog.tomography.compute_density_matrix(schedule, qpu, psi_0=None)

Simulate the evolution of a system specified by a Schedule via QutipQPU or AnalogQPU, which can be noiseless, with jump operators or with stochastic noise, and return the final density matrix \(\rho\). The initial pure state psi_0 can also be specified.

Note

A real quantum processing unit (QPU) would never return the density matrix. It is not recommended to base computations on this method.

Parameters

  • schedule (Schedule) – the schedule encoding the Hamiltonian and the evolution time

  • qpu (QutipQPU or AnalogQPU) – the QPU to perform the simulation

  • psi_0 (np.array or string, optional) – initial pure state. Dafaults to \(\left|0 \dots 0\right>\).

Returns

density matrix

Return type

np.array

Note

This method is available as an application in Qaptiva Access.