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】

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