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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-4215
DTSTART:20161006T150000Z
DURATION:PT1H0M0S
DTSTAMP:20210121T221534Z
LAST-MODIFIED:20161003T134021Z
LOCATION:5310 Chamerlin Hall
SUMMARY: Scaling analysis and instantons for quantum spin tunneling an
d Quantum Monte Carlo simulations\, R. G. Herb Condensed Matter Semina
r\, 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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