Spectroscopy of a driven solid-state qubit coupled to a structured environment
Abstract
We study the asymptotic dynamics of a driven spin-boson system where the environment is formed by a broadened localized mode. Upon exploiting an exact mapping, an equivalent formulation of the problem in terms of a quantum two-state system (qubit) coupled to a harmonic oscillator which is itself Ohmically damped, is found. We calculate the asymptotic population difference of the two states in two complementary parameter regimes. For weak damping and low temperature, a perturbative Floquet-Born-Markovian master equation for the qubit-oscillator system can be solved. We find multi-photon resonances corresponding to transitions in the coupled quantum system and calculate their line-shape analytically. In the complementary parameter regime of strong damping and/or high temperatures, non-perturbative real-time path integral techniques yield analytic results for the resonance line shape. In both regimes, we find very good agreement with exact results obtained from a numerical real-time path-integral approach. Finally, we show for the case of strong detuning between qubit and oscillator that the width of the -photon resonance scales with the -th Bessel function of the driving strength in the weak-damping regime.
Cite
@article{arxiv.cond-mat/0412194,
title = {Spectroscopy of a driven solid-state qubit coupled to a structured environment},
author = {M. C. Goorden and M. Thorwart and M. Grifoni},
journal= {arXiv preprint arXiv:cond-mat/0412194},
year = {2009}
}
Comments
13 pages, 5 figures