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CATEGORIES:CQIF Seminar
SUMMARY:When is a Hamiltonian Stoquastic? - Joel Klassen\,
TU Delft
DTSTART;TZID=Europe/London:20190523T141500
DTEND;TZID=Europe/London:20190523T151500
UID:TALK124303AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/124303
DESCRIPTION:Finding the lowest energy of a Hamiltonian is a ha
rd problem in general\, however for many physical
systems quantum Monte Carlo methods can often be e
ffectively applied to determine the lowest energy
of a Hamiltonian\, and it is commonly understood t
hat the absence of a sign problem is a requisite c
ondition for the success of these methods. The not
ion of stoquastic Hamiltonians was introduced with
the aim of categorizing those Hamiltonians which
do not suffer from the sign problem. Indeed\, the
study of stoquastic Hamiltonians in the context of
computational complexity theory has lent support
to the notion that stoquastic Hamiltonians are som
ehow "simpler" than generic Hamiltonians. Importan
tly\, the property of being stoquastic makes itsel
f manifest only in a particular basis choice. In t
his work we explore how hard it is\, from a comput
ational complexity perspective\, to find such a ch
oice of basis. I will present an outline of an eff
icient algorithm for deciding if a 2-local Hamilto
nian\, with no 1-local terms\, is stoquastic in so
me local basis.
LOCATION:MR13\, Centre for Mathematical Sciences\, Wilberfo
rce Road\, Cambridge
CONTACT:Johannes Bausch
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