Impurity dephasing in a Bose-Hubbard model

Year: 2021

Authors: Caleffi F.; Capone M.; de Vega I.; Recati A.

Autors Affiliation: Int Sch Adv Studies SISSA, Via Bonomea 265, I-34136 Trieste, Italy; CNR IOM Democritos, Via Bonomea 265, I-34136 Trieste, Italy; Ludwig Maximilians Univ Munchen, Dept Phys, Theresienstr 37, D-80333 Munich, Germany; Ludwig Maximilians Univ Munchen, Arnold Sommerfeld Ctr Theoret Phys, Theresienstr 37, D-80333 Munich, Germany; IQM Germany GmbH, Nymphenburgerstr 86, D-80636 Munich, Germany; Univ Trento, INO CNR BEC Ctr, Dipartimento Fis, Via Sommar 14, I-38123 Povo, Trento, Italy; Univ Trento, Trento Inst Fundamental Phys & Applicat, INFN, Dipartimento Fis, Via Sommar 14, I-38123 Povo, Trento, Italy.

Abstract: We study the dynamics of a two-level impurity embedded in a two-dimensional Bose-Hubbard (BH) model at zero temperature from an open quantum system perspective. Results for the decoherence across the whole phase diagram are presented, with a focus on the critical region close to the transition between superfluid and Mott insulator. In particular we show how the decoherence and the deviation from a Markovian behaviour are sensitive to whether the transition is crossed at commensurate or incommensurate densities. The role of the spectrum of the BH environment and its non-Gaussian statistics, beyond the standard independent boson model, is highlighted. Our analysis resorts on a recently developed method (2020 Phys. Rev. Res. 2 033276) – closely related to slave boson approaches – that enables us to capture the correlations across the whole phase diagram. This semi-analytical method provides us with a deep insight into the physics of the spin decoherence in the superfluid and Mott phases as well as close to the phase transitions.

Journal/Review: NEW JOURNAL OF PHYSICS

Volume: 23 (3)      Pages from: 033018-1  to: 033018-17

KeyWords: open quantum systems; pure dephasing; cold gases in optical lattices; Bose-Hubbard model; quasiparticles and collective excitations
DOI: 10.1088/1367-2630/abe080

Citations: 6
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here