Qubit Decoherence and Non-Markovian Dynamics at Low Temperatures via an Effective Spin-Boson Model
Abstract
Quantum Brownian oscillator model (QBM), in the Fock-space representation, can be viewed as a multi-level spin-boson model. At sufficiently low temperature, the oscillator degrees of freedom are dynamically reduced to the lowest two levels and the system behaves effectively as a two-level (E2L) spin-boson model (SBM) in this limit. We discuss the physical mechanism of level reduction and analyze the behavior of E2L-SBM from the QBM solutions. The availability of close solutions for the QBM enables us to study the non-Markovian features of decoherence and leakage in a SBM in the non-perturbative regime (e.g. without invoking the Born approximation) in better details than before. Our result captures very well the characteristic non-Markovian short time low temperature behavior common in many models.
Keywords
Cite
@article{arxiv.quant-ph/0405147,
title = {Qubit Decoherence and Non-Markovian Dynamics at Low Temperatures via an Effective Spin-Boson Model},
author = {K. Shiokawa and B. L. Hu},
journal= {arXiv preprint arXiv:quant-ph/0405147},
year = {2009}
}
Comments
19 pages, 8 figures