Quantum tricritical point emerging in the spin-boson model with two dissipative spins in staggered biases
Abstract
We study the spin-boson model (SBM) with two spins in staggered biases by a numerically exact method based on variational matrix product states. Several observables such as the magnetization, the entanglement entropy between the two spins and the bosonic environment, the ground-state energy, as well as the correlation function for two spins are calculated exactly. The characteristics of these observables suggest that the staggered biases can drive the 2nd-order quantum phase transition (QPT) to the 1st-order QPT in the sub-Ohmic SBM, while the Kosterlitz-Thouless QPT in the Ohmic SBM goes directly to the 1st-order one. A quantum tricritical point, where the continuous QPT meets the 1st-order one, can then be detected. It is found that the staggered biases would not change the universality of { the phase transition in this model} below the quantum tricritical point.
Keywords
Cite
@article{arxiv.2001.07916,
title = {Quantum tricritical point emerging in the spin-boson model with two dissipative spins in staggered biases},
author = {Yan-Zhi Wang and Shu He and Liwei Duan and Qing-Hu Chen},
journal= {arXiv preprint arXiv:2001.07916},
year = {2021}
}
Comments
8 pages, 9 figures. arXiv admin note: text overlap with arXiv:2001.02166