Phonon-induced modification of quantum criticality

Article

关键词: CRITICAL-BEHAVIOR;    CRITICAL EXPONENTS;    PHASE-TRANSITIONS;    RENORMALIZATION;    LATTICE;   

DOI  :  10.1103/PhysRevB.106.035154

来源: SCIE

【 摘 要 】

We study the effect of acoustic phonons on the quantum phase transition in the O(N) model. We develop a renormalization group (RG) analysis near (3+1) space-time dimensions and derive the RG equations using an epsilon expansion. Our results indicate that when the number of flavors of the underlying O(N) model exceeds a critical number N-c = 4, the quantum transition remains second-order of the Wilson-Fisher type while, for N <= 4, it is a weakly first-ordertransition. We characterize this weakly first-order transition by a length scale xi*, below which the behavior appears to be critical. At finite temperatures for N <= 4, a tricritical point separates the weakly first-order and second-order transitions.

【 授权许可】

Free