CHSH

The CHSH experiment is used to demonstrate the existence of entanglement via the violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality.

Parameters

class qibocal.protocols.two_qubit_interaction.chsh.protocol.CHSHParameters(bell_states: list[int], ntheta: int, native: bool | None = True)[source]

CHSH runcard inputs.

bell_states: list[int]

List with Bell states to compute CHSH. The following notation it is used: 0 -> |00>+|11> 1 -> |00>-|11> 2 -> |10>-|01> 3 -> |10>+|01>

ntheta: int

Number of angles probed linearly between 0 and 2 pi.

native: bool | None = True

If True a circuit will be created using only GPI2 and CZ gates.

hardware_average: bool = False

By default hardware average will be performed.

nshots: int

Number of executions on hardware.

relaxation_time: float

Wait time for the qubit to decohere back to the gnd state.

Example

It follows a runcard example of this experiment.

- id: chsh
  operation: chsh
  targets: [[0, 1]]
  parameters:
      bell_states: [0, 1, 2, 3]
      ntheta: 20
      native: True

The expected output is the following:

../_images/chsh.png

Note

The mitigated line will appear if the readout mitigation matrix is available in the platform calibration. This can be obtained using the Readout mitigation matrix routine.