Dynamical quantum phase transition in a bosonic system with long-range interactions
Anno: 2021
Autori: Syed M., Enss T., Defenu N.
Affiliazione autori: Heidelberg Univ, Inst Theoret Phys, D-69120 Heidelberg, Germany; Swiss Fed Inst Technol, Inst Theoret Phys, Wolfgang Pauli Str 27, CH-8093 Zurich, Switzerland.
Abstract: In this paper, we investigate the dynamical quantum phase transitions appearing in the Loschmidt echo and the time-dependent order parameter of a quantum system of harmonically coupled degenerate bosons as a function of the power-law decay sigma of long-range interactions. Following a sudden quench, the nonequilibrium dynamics of this system are governed by a set of nonlinear coupled Ermakov equations. To solve them, we develop an analytical approximation valid at late times. Based on this approximation, we show that the emergence of a dynamical quantum phase transition hinges on the generation of a finite mass gap following the quench, starting from a massless initial state. In general, we can define two distinct dynamical phases characterized by the finiteness of the post-quench mass gap. The Loschmidt echo exhibits periodical nonanalytic cusps whenever the initial state has a vanishing mass gap and the final state has a finite mass gap. These cusps are shown to coincide with the maxima of the time-dependent long-range correlations.
Giornale/Rivista: PHYSICAL REVIEW B
Volume: 103 (6) Da Pagina: 64306-1 A: 64306-9
Maggiori informazioni: This work is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), project-ID 273811115 (SFB1225 ISOQUANT) and under Germany’s Excellence Strategy EXC2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster).Parole chiavi: Spherical ModelDOI: 10.1103/PhysRevB.103.064306Citazioni: 17dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2025-06-29Riferimenti tratti da Isi Web of Knowledge: (solo abbonati)
