Quantum phase transition and eigen microstate condensation in the quantum Rabi model

Gaoke Hu, Maoxin Liu and Xiaosong Chen

Physica A: Statistical Mechanics and its Applications, 2023, vol. 630, issue C

Abstract: We introduce an eigen microstate approach (EMA) in the quantum system to describe the quantum phase transition without knowing the order parameter. Phases of a quantum system are determined by the so-called eigen microstates and their corresponding eigenvalues, which satisfy scaling relations in the critical regime. The quantum Rabi model (QRM) is taken as an example to demonstrate the validity of the EMA. Using both analytical and numerical calculations, we obtain the critical point, critical exponents, and scaling functions of the superradiant phase transition in the QRM. It suggests that a new phase emergency can be interpreted as a condensation of a specific eigen microstate. We expect that, in further studies, the EMA will be applied to more complex quantum phase transition problems in which order parameters cannot be easily defined.

Keywords: Eigen microstate approach; Quantum phase transition; Quantum Rabi model (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378437123007653
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:630:y:2023:i:c:s0378437123007653

DOI: 10.1016/j.physa.2023.129210

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 ().