BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Zlatko Papic (University of Leeds)
DTSTART:20200610T100000Z
DTEND:20200610T110000Z
DTSTAMP:20260423T040006Z
UID:QM3/5
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/QM3/5/">Quan
 tum many-body scars: a new form of weak ergodicity breaking in constrained
  quantum systems</a>\nby Zlatko Papic (University of Leeds) as part of Qua
 ntum Matter meets Maths (IST\, Lisbon)\n\n\nAbstract\nRecent experiments o
 n large chains of Rydberg atoms [1] have demonstrated the possibility of r
 ealising one-dimensional\, kinetically constrained quantum systems. It was
  found that such systems exhibit surprising signatures of non-ergodic dyna
 mics\, such as robust periodic revivals in global quenches from certain in
 itial states. This weak form of ergodicity breaking has been interpreted a
 s a manifestation of "quantum many-body scars" [2]\, i.e.\, the many-body 
 analogue of unstable classical periodic orbits of a single particle in a c
 haotic stadium billiard. Scarred many-body eigenstates have been shown to 
 exhibit a range of unusual properties which violate the Eigenstate Thermal
 isation Hypothesis\, such as equidistant energy separation\, anomalous exp
 ectation values of local observables and subthermal entanglement entropy. 
 I will demonstrate that these properties can be understood using a tractab
 le model based on a single particle hopping on the Hilbert space graph\, w
 hich formally captures the idea that scarred eigenstates form a representa
 tion of a large  spin that is embedded in a thermalising many-body system.
  I will show that this picture allows to construct a more general family o
 f scarred models where the fundamental degree of freedom is a quantum cloc
 k [3]. These results suggest that scarred many-body bands give rise to a n
 ew universality class of constrained quantum dynamics\, which opens up opp
 ortunities for creating and manipulating novel states with long-lived cohe
 rence in systems that are now amenable to experimental study.<br>\n\n[1] H
 . Bernien et al.\, Nature 551\, 579 (2017).<br>\n[2] C. J. Turner\, A. A. 
 Michailidis\, D. A. Abanin\, M. Serbyn\, Z. Papic\, Nat. Phys. 14\, 745 (2
 018).<br>\n[3] Kieran Bull\, Ivar Martin\, and Z. Papic\, Phys. Rev. Lett.
  123\, 030601 (2019).\n
LOCATION:https://researchseminars.org/talk/QM3/5/
END:VEVENT
END:VCALENDAR