Parametric control of a superconducting flux qubit

TL;DR

This paper demonstrates parametric control of a superconducting flux qubit using two-frequency microwave pulses, enabling broader control and exploration of nonlinear quantum phenomena.

Contribution

It introduces a novel method of controlling flux qubits via parametric transitions with two-frequency microwaves, expanding the control capabilities.

Findings

Observation of Rabi oscillations from parametric transitions

Detection of multi-photon Rabi oscillations up to four-photon resonances

Broader microwave frequency range for qubit control

Abstract

Parametric control of a superconducting flux qubit has been achieved by using two-frequency microwave pulses. We have observed Rabi oscillations stemming from parametric transitions between the qubit states when the sum of the two microwave frequencies or the difference between them matches the qubit Larmor frequency. We have also observed multi-photon Rabi oscillations corresponding to one- to four-photon resonances by applying single-frequency microwave pulses. The parametric control demonstrated in this work widens the frequency range of microwaves for controlling the qubit and offers a high quality testing ground for exploring nonlinear quantum phenomena.