Entropic quantifier of spin–boson nonclassicality. (21st October 2022)

• Record Type: Journal Article
• Authors: Zhang, Yue; Jing, Boxuan; He, Qiongyi; Luo, Shunlong
• Is Part Of: Journal of physics. Volume 55:Number 42(2022)
• Publication Date: 2022-10-21
• Subjects: spin–boson systems -- nonclassicality -- entropy excess -- Tsallis entropy -- quantum phase transition; Mathematical physics -- Periodicals; Statistical physics -- Periodicals; Quantum theory -- Periodicals; Matter -- Properties -- Periodicals; 530.105
• DOI: 10.1088/1751-8121/ac96dd
• Languages: English
• ISSNs: 1751-8113

Abstract

Abstract: Spin systems interacting with boson environments are ubiquitous in nature. To what extent quantum states in such systems depart from classicality is becoming an increasingly important issue. Here, we study nonclassicality in systems involving the interaction between a spin and a boson mode. We introduce a simple and effective method for quantifying spin–boson nonclassicality in terms of the entropy excess between the classical and the quantum Tsallis entropy. The method can be naturally extended to more general systems. Fundamental properties of the nonclassicality quantifier are revealed, which render it reasonable for spin–boson states. Basic features are illustrated by a variety of typical spin–boson states. As applications, we further investigate spin–boson nonclassicality in the Dicke model, which sheds light on the normal-superradiant phase transition and quantum metrology.