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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-4215
DTSTART:20161006T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260317T062035Z
LAST-MODIFIED:20161003T134021Z
LOCATION:5310 Chamerlin Hall
SUMMARY:Scaling analysis and instantons for quantum spin tunneling and
  Quantum Monte Carlo simulations\, R. G. Herb Condensed Matter Seminar
 \, Vadim Smelyanskyi\, Google
DESCRIPTION:We will provide an overview   of recent results of Google 
 quantum computing  team on the role of collective tunneling in quantum
  annealing algorithm.  We will discuss the comparison of theory and ex
 periments  performed on DWave machine.  We will describe  an instanton
 ic calculus for the thermally-assisted tunneling decay rate in a fully
  connected quantum spin model. We show that the tunneling decay proble
 m can be mapped onto the Kramers escape problem of a classical random 
 dynamical field. This dynamical field is simulated efficiently by Path
  Integral Quantum Monte Carlo (QMC). We show that the exponential scal
 ing with the number of spins of the quantum tunneling rate and the esc
 ape rate of the QMC process are identical. We provide further examples
  where QMC has quadratic speed up in scaling over quantum tunneling.
URL:https://www.physics.wisc.edu/events/?id=4215
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