Quasi-Bell states in a strongly coupled qubit–oscillator system and their delocalization in the phase space

R. Chakrabarti and B. Virgin Jenisha

Physica A: Statistical Mechanics and its Applications, 2015, vol. 435, issue C, 95-110

Abstract: We study the evolution of bipartite entangled quasi-Bell states in a strongly coupled qubit–oscillator system in the presence of a static bias, and extend it to the ultra-strong coupling regime. Using the adiabatic approximation the reduced density matrix of the qubit is obtained for the strong coupling domain in closed form that involves linear combinations of the Jacobi theta functions. The reduced density matrix of the oscillator yields the phase space Husimi Q-distribution. In the strong coupling regime the Q-function evolves to uniformly separated macroscopically distinct Gaussian peaks representing ‘kitten’ states at certain specified times that depend on multiple time scales present in the interacting system. For the ultra-strong coupling realm the delocalization in the phase space of the oscillator is studied by using the Wehrl entropy and the complexity of the quantum state. For a small phase space amplitude the entangled quasi-Bell state develops, during its time evolution, squeezing property and nonclassicality of the photon statistics which are measured by the quadrature variance and the Mandel parameter, respectively.

Keywords: Adiabatic approximation; Reduced density matrices; Theta functions; Wehrl entropy; Transient ‘kitten’ states; Nonclassicality (search for similar items in EconPapers)
Date: 2015
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378437115003957
Full text for ScienceDirect subscribers only. Journal offers the option of making the article available online on Science direct for a fee of $3,000

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:phsmap:v:435:y:2015:i:c:p:95-110

DOI: 10.1016/j.physa.2015.04.027

Access Statistics for this article

Physica A: Statistical Mechanics and its Applications is currently edited by K. A. Dawson, J. O. Indekeu, H.E. Stanley and C. Tsallis

More articles in Physica A: Statistical Mechanics and its Applications from Elsevier
Bibliographic data for series maintained by Catherine Liu ().