Measure detuning induced by flux pulse

The frequency of a qubit can be modified by applying a flux pulse. This mechanism is often used to tune the qubit to a desired frequency. By bringing two qubits closer in frequency it possible to generate natively gates such as CZ or iSWAP.

In this experiment we measure the detuning with a Ramsey-like sequence where instead of just waiting we apply a flux pulse of duration \(\tau\). The detuning is extracted from the oscillation frequency of the excited state population.

\[p_e(t) =\frac{1}{2} \left( 1 + \cos\left(\Delta \omega t \right) \right)\]

Parameters

class qibocal.protocols.flux_dependence.flux_gate.FluxGateParameters(duration_min: float, duration_max: float, duration_step: float, flux_pulse_amplitude: float)

FluxGate runcard inputs.

duration_min: float

Minimum flux pulse duration.

duration_max: float

Maximum flux duration start.

duration_step: float

Flux pulse duration step.

flux_pulse_amplitude: float

Flux pulse amplitude.

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

A possible runcard to launch a FluxGate experiment could be the following:

- id: flux_gate
  operation: flux_gate
  parameters:
    duration_min: 10
    duration_max: 100
    duration_step: 10
    flux_pulse_amplitude: 0.2

The expected output is the following:

Requirements

• Single Shot Experiments