Quantum phase transition of the sub-Ohmic rotor model | |
Article | |
关键词: LONG-RANGE INTERACTIONS; BLACKBODY RADIATION-FIELD; SPIN-BOSON MODEL; CRITICAL EXPONENTS; SPHERICAL MODEL; CRITICALITY; OSCILLATOR; IMPURITY; SYSTEMS; | |
DOI : 10.1103/PhysRevB.84.195136 | |
来源: SCIE |
【 摘 要 】
We investigate the behavior of an N-component quantum rotor coupled to a bosonic dissipative bath having a sub-Ohmic spectral density J (omega) alpha omega(s) with s < 1. With increasing dissipation strength, this system undergoes a quantum phase transition from a delocalized phase to a localized phase. We determine the exact critical behavior of this transition in the large-N limit. For 1 > s > 1/2, we find nontrivial critical behavior corresponding to an interacting renormalization group fixed point, while we find mean-field behavior for s < 1/2. The results agree with those of the corresponding long-range interacting classical model. The quantum-to-classical mapping is therefore valid for the sub-Ohmic rotor model.
【 授权许可】
Free