qit.plot.state_trajectory

qit.plot.state_trajectory(traj, reset=True, ax=None, color='b', marker='')

Plot a state trajectory in the correlation representation.

  • For a single-qubit system, plots the trajectory in the Bloch sphere.

  • For a two-qubit system, plots the reduced single-qubit states (in Bloch spheres), as well as the interqubit correlations.

traj can be obtained e.g. by using one of the continuous-time state propagation functions and feeding the results to state.bloch_vector.

Parameters
  • traj (list[array], array) – generalized Bloch vector of the quantum state, or a list of them representing a trajectory

  • reset (bool) – if False, adds another trajectory to the axes without erasing .

  • ax (Axes) – axes to plot in, or None in which case a new figure is created

Returns

axes containing the plot

Return type

Axes

Example 1: Trajectory of the state s under the Hamiltonian H:

out = s.propagate(H, t, lambda s, H: s.bloch_vector())
state_trajectory(out)

Example 2: Just a single state s:

state_trajectory(s.bloch_vector())