Exploring the Effect of Noise on the Berry Phase

TL;DR

This study investigates how noise affects the geometric phase in a superconducting qubit, revealing that path-distorting fluctuations cause dephasing, but geometric phases are more robust than dynamic phases, highlighting their potential in quantum technologies.

Contribution

It demonstrates experimentally that geometric phases are less susceptible to noise-induced dephasing compared to dynamic phases in superconducting qubits.

Findings

Path-distorting noise causes geometric dephasing.

Geometric phases are more robust than dynamic phases under noise.

Results suggest potential for geometric phases in quantum applications.

Abstract

We make use of a superconducting qubit to study the effects of noise on adiabatic geometric phases. The state of the system, an effective spin one-half particle, is adiabatically guided along a closed path in parameter space and thereby acquires a geometric phase. By introducing artificial fluctuations in the control parameters, we measure the geometric contribution to dephasing for a variety of noise powers and evolution times. Our results clearly show that only fluctuations which distort the path lead to geometric dephasing. In a direct comparison with the dynamic phase, which is path-independent, we observe that the adiabatic geometric phase is less affected by noise-induced dephasing. This observation directly points towards the potential of geometric phases for quantum gates or metrological applications.