We study the nonequilibrium phase diagram and the dynamical phase transitions occurring during the prethermalization of nonintegrable quantum spin chains, subject to either quantum quenches or linear ramps of a relevant control parameter. We consider spin systems in which long-range ferromagnetic interactions compete with short-range, integrability-breaking terms. We capture the prethermal stages of the nonequilibrium evolution via a time-dependent spin-wave expansion at leading order in the spin-wave density. In order to access regimes with strong integrability breaking, instead, we perform numerical simulations based on the time-dependent variational principle with matrix product states. By investigating a large class of quantum spin models, we demonstrate that nonequilibrium fluctuations can significantly affect the dynamics near critical points of the phase diagram, resulting in a chaotic evolution of the collective order parameter, akin to the dynamics of a classical particle in a multiple-well potential subject to quantum friction. We also elucidate the signature of this novel dynamical phase on the time-dependent correlation functions of the local order parameter. We finally establish a connection with the notion of dynamical quantum phase transition associated with a possible nonanalytic behavior of the return probability amplitude, or Loschmidt echo, showing that the latter displays cusps whenever the order parameter vanishes during its real-time evolution.

Impact of nonequilibrium fluctuations on prethermal dynamical phase transitions in long-range interacting spin chains / Lerose, Alessio; Žunkovič, Bojan; Marino, Jamir; Gambassi, Andrea; Silva, Alessandro. - In: PHYSICAL REVIEW. B. - ISSN 2469-9950. - 99:4(2019), pp. 1-28. [10.1103/PhysRevB.99.045128]

Impact of nonequilibrium fluctuations on prethermal dynamical phase transitions in long-range interacting spin chains

Lerose, Alessio;Žunkovič, Bojan;Marino, Jamir;Gambassi, Andrea;Silva, Alessandro
2019-01-01

Abstract

We study the nonequilibrium phase diagram and the dynamical phase transitions occurring during the prethermalization of nonintegrable quantum spin chains, subject to either quantum quenches or linear ramps of a relevant control parameter. We consider spin systems in which long-range ferromagnetic interactions compete with short-range, integrability-breaking terms. We capture the prethermal stages of the nonequilibrium evolution via a time-dependent spin-wave expansion at leading order in the spin-wave density. In order to access regimes with strong integrability breaking, instead, we perform numerical simulations based on the time-dependent variational principle with matrix product states. By investigating a large class of quantum spin models, we demonstrate that nonequilibrium fluctuations can significantly affect the dynamics near critical points of the phase diagram, resulting in a chaotic evolution of the collective order parameter, akin to the dynamics of a classical particle in a multiple-well potential subject to quantum friction. We also elucidate the signature of this novel dynamical phase on the time-dependent correlation functions of the local order parameter. We finally establish a connection with the notion of dynamical quantum phase transition associated with a possible nonanalytic behavior of the return probability amplitude, or Loschmidt echo, showing that the latter displays cusps whenever the order parameter vanishes during its real-time evolution.
2019
99
4
1
28
045128
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.045128
https://arxiv.org/pdf/1807.09797.pdf
Lerose, Alessio; Žunkovič, Bojan; Marino, Jamir; Gambassi, Andrea; Silva, Alessandro
File in questo prodotto:
File Dimensione Formato  
69-PhysRevB.99.045128.pdf

non disponibili

Tipologia: Versione Editoriale (PDF)
Licenza: Non specificato
Dimensione 9.22 MB
Formato Adobe PDF
9.22 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
1807.09797v2.pdf

accesso aperto

Tipologia: Documento in Post-print
Licenza: Non specificato
Dimensione 5.47 MB
Formato Adobe PDF
5.47 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/87798
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 56
  • ???jsp.display-item.citation.isi??? 53
social impact