Weak localization and conductance fluctuations-like effects in Qubits driven by biharmonic signals

ALEJANDRO FERRON; DANIEL DOMINGUEZ; MARIA JOSE SANCHEZ

Journal of Physics: Conference Series

Institute of Physics (IOP)

Lugar: London; Año: 2014 vol. 568 p. 52028 - 52028

1742-6588

We investigate the effect of broken time reversal symmetry in flux qubits driven by abiharmonic magnetic flux signal with a phase lag. In the regime of large relaxation times,we explicitly compute the transition rate between the ground and the excited state, accountingfor decoherence as a classical noise. Through a direct analogy between interference effects at theavoided level crossing and scattering events in weakly disordered electronic mesoscopic systems,the transition rate plays the role of an effective transmittance while the phase lag acts as atime reversal control parameter. Clear signatures of both weak localization and conductancefluctuations-like effects are predicted. Their behavior is studied as a function of the coherencerate, and a comparison with recent experimental results is performed. Our study shows thatit is decoherence, and not the driving protocol, what limits the experimental detection of weaklocalization effects.