Instituto de Ciencia de Materiales de Madrid
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Qubit interference at avoided crossings: The role of driving shape and bath coupling

Ralf Blattmann, Peter Hänggi, and Sigmund Kohler
Phys. Rev. A 91, 042109 (2015)

We derive the structure of Landau-Zener-Stückelberg-Majorana (LZSM) interference patterns for a qubit that experiences quantum dissipation and is additionally subjected to time-periodic but otherwise general driving. A spin-boson Hamiltonian serves as the model, which we treat with a Bloch-Redfield master equation in the Floquet basis. It predicts resonance peaks whose form depends significantly on the operator through which the qubit couples to the bath. The Fourier transforms of the LZSM patterns exhibit arc structures which reflect the shape of the driving. These features are captured by an effective time-independent Bloch equation which provides an analytical solution. Moreover, we determine the decay of these arcs as a function of dissipation strength and temperature.
arXiv:1409.5237 [quant-ph]

[ICMM-CSIC] [Condensed Matter Theory]
last modified: 23.11.2017 by Sigmund Kohler