Quantum speed limit in the thermal spin-boson system with and without tunneling term
- PDF / 1,379,669 Bytes
- 17 Pages / 439.37 x 666.142 pts Page_size
- 18 Downloads / 142 Views
Quantum speed limit in the thermal spin-boson system with and without tunneling term Sh. Dehdashti1,2 · F. Yasar2
· M. Bagheri Harouni3 · A. Mahdifar4 · B. Mirza5
Received: 30 May 2020 / Accepted: 11 August 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract In this paper, we study the spin-bosonic model, with and without tunneling terms, in detail. The spin-bosonic model without tunneling is studied by using the thermofield dynamics approach. Indeed, by considering temperature, we show that environmental states, while they become entangled with system, approach thermal coherent states with different phases. In addition, by considering the tunneling term, we study the interplay of the environmental cut-off frequency as well as the impacts of environmental temperature on the quantum speed limit in both cases, i.e., spin-boson system with and without tunneling term. In these studies, we indicate temperature play more important role in compare with cut-off frequency to control the quantumness of a spin system. Keywords Spin-boson system · Quantum speed limit · Tunneling term
1 Introduction Spin-boson model that is a central spin system interacting with a boson environment of harmonic oscillators, is one of the relevant physical systems for both its theoretical aspects and its applications. Concerning theoretical aspects, the spin-boson model without tunneling term exhibits features characteristic of the pure decoherence process,
B
F. Yasar [email protected]
1
School of Information Systems, Queensland University of Technology, Brisbane, Australia
2
Materials Science and Engineering Department, College of Engineering, University of Wisconsin Madison, Madison, WI 53706, USA
3
Department of Physics, Faculty of Science, University of Isfahan, Hezar Jerib St., Isfahan 81746-73441, Iran
4
Department of Physics, Faculty of science, Shahrekord University, Shahrekord 88186-34141, Iran
5
Department of Physics, Isfahan University of Technology, Isfahan 84156-83111, Iran 0123456789().: V,-vol
123
308
Page 2 of 17
Sh. Dehdashti et al.
i.e., quantum-to-classical transition; thus, it is an ideal candidate for the study of decoherence process, which characterizes the quantum-to-classical transition, in twolevel systems [1–6]. Indeed, the simplified spin-boson model, i.e., the spin-boson system without tunneling term, is one of the best models to exhibit the characteristic features of the quantum-to-classical transition; in other words, Zurek indicates the quantum-to-classical transition can be modeled as a result of correlation between the quantum system states with associated environmental states, which, in the spin system are coherent states [7–9]. Note that, according to the definition of the coherent states, they are the nearest states to the classical ones. In a word, by this model we can demonstrate that quantum states of a two-level system become entangled with the associated states of the environment which are coherent states with different phases; consequently, the interferen
Data Loading...
