Quantum emulation of coherent backscattering in a system of superconducting qubits

TL;DR

This paper demonstrates how highly-coherent superconducting qubits can emulate quantum interference phenomena like weak localization and universal conductance fluctuations through multi-pass Landau-Zener transitions, showcasing quantum emulation capabilities.

Contribution

It introduces a method to emulate quantum interference effects in superconducting qubits using non-adiabatic control, achieving both WL and UCF phenomena.

Findings

Observed dip and peak in transition rate corresponding to WL and UCF

Higher qubit coherence enabled simultaneous emulation of both effects

Demonstrated quantum emulation using non-adiabatic control techniques

Abstract

In condensed matter systems, coherent backscattering and quantum interference in the presence of time-reversal symmetry lead to well-known phenomena such as weak localization (WL) and universal conductance fluctuations (UCF). Here we use multi-pass Landau-Zener transitions at the avoided crossing of a highly-coherent superconducting qubit to emulate these phenomena. The average and standard deviation of the qubit transition rate exhibit a dip and peak when the driving waveform is time-reversal symmetric, analogous to WL and UCF, respectively. The higher coherence of this qubit enabled the realization of both effects, in contrast to earlier work arXiv:1204.6428, which successfully emulated UCF, but did not observe WL. This demonstration illustrates the use of non-adiabatic control to implement quantum emulation with superconducting qubits.