Quantum simulation of coherent backscattering in a system of superconducting qubits

Ana Laura Gramajo, Dan Campbell, Bharath Kannan, David K. Kim, Alexander Melville, Bethany M. Niedzielski, Jonilyn L. Yoder, María José Sánchez, Daniel Domínguez, Simon Gustavsson, William D. Oliver

Published 2019-12-28Version 1

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, corresponding 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.