Tuning between continuous time crystals and many-body scars in long-range XYZ spin chains.

Journal Article · 29 September 2022 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.129.140602· OSTI ID:1923078

Bull, Kieran; Hallam, Andrew; Papic, Zlatko; Martin, Ivar

Persistent oscillatory dynamics in nonequilibrium many-body systems is a tantalizing manifestation of ergodicity breakdown that continues to attract much attention. Recent works have focused on two classes of such systems: discrete time crystals and quantum many-body scars (QMBS). While both systems host oscillatory dynamics, its origin is expected to be fundamentally different: discrete time crystal is a phase of matter which spontaneously breaks the Z 2 symmetry of the external periodic drive, while QMBS span a subspace of nonthermalizing eigenstates forming an su(2) algebra representation. Here, we ask a basic question: is there a physical system that allows us to tune between these two dynamical phenomena? In contrast to much previous work, we investigate the possibility of a continuous time crystal (CTC) in undriven, energy-conserving systems exhibiting prethermalization. We introduce a long-range XYZ spin model and show that it encompasses both a CTC phase as well as QMBS. We map out the dynamical phase diagram using numerical simulations based on exact diagonalization and time-dependent variational principle in the thermodynamic limit. We identify a regime where QMBS and CTC order coexist, and we discuss experimental protocols that reveal their similarities as well as key differences.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: Engineering and Physical Sciences Research Council (EPSRC); Leverhulme Trust; USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1923078
• Journal Information: Physical Review Letters, Vol. 129, Issue 14
• Country of Publication: United States
• Language: English