  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.
