Communication: Spin-boson model with diagonal and off-diagonal coupling to two independent baths: Ground-state phase transition in the deep sub-Ohmic regime

Journal Article · Mon Apr 28 00:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4873351· OSTI ID:22253016

Zhao, Yang; Zhao, Yang ^[1]; Yao, Yao ^[2]; Chernyak, Vladimir ^[3]

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1. Division of Materials Science, Nanyang Technological University, Singapore 639798 (Singapore)
2. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433 (China)
3. Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States)

We investigate a spin-boson model with two boson baths that are coupled to two perpendicular components of the spin by employing the density matrix renormalization group method with an optimized boson basis. It is revealed that in the deep sub-Ohmic regime there exists a novel second-order phase transition between two types of doubly degenerate states, which is reduced to one of the usual types for nonzero tunneling. In addition, it is found that expectation values of the spin components display jumps at the phase boundary in the absence of bias and tunneling.

• OSTI ID: 22253016
• Journal Information: Journal of Chemical Physics, Vol. 140, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOSONS
DENSITY MATRIX
EXPECTATION VALUE
GROUND STATES
PHASE TRANSFORMATIONS
SPIN
TUNNEL EFFECT