Coherent oscillations in a superconducting tunable flux qubit manipulated without microwaves

TL;DR

This paper demonstrates fast, coherent oscillations in a superconducting flux qubit manipulated by magnetic flux pulses, enabling rapid quantum gates with high resilience to noise.

Contribution

It introduces a method to control a tunable flux qubit using magnetic flux pulses instead of microwaves, achieving faster gate operations and improved noise insensitivity.

Findings

Oscillation frequencies from 6 GHz to 21 GHz tunable via flux pulse amplitude

Quantum gates realized in less than 100 ps

Enhanced noise resilience of the flux qubit

Abstract

We experimentally demonstrate the coherent oscillations of a tunable superconducting flux qubit by manipulating its energy potential with a nanosecond-long pulse of magnetic flux. The occupation probabilities of two persistent current states oscillate at a frequency ranging from 6 GHz to 21 GHz, tunable via the amplitude of the flux pulse. The demonstrated operation mode allows to realize quantum gates which take less than 100 ps time and are thus much faster compared to other superconducting qubits. An other advantage of this type of qubit is its insensitivity to both thermal and magnetic field fluctuations.