BEGIN:VCALENDAR VERSION:2.0 PRODID:Data::ICal 0.22 BEGIN:VEVENT DESCRIPTION:Adolfo del Campo \, Ikerbasque & DIPC\n\n
The \;number of topological defects created
in a system driven through a \;quantum phase transition exhibits a pow
er-law scaling with the driving \;time. This universal scaling law is
the key prediction of the \;Kibble-Zurek mechanism (KZM)\, and testing
it using a hardware-based \;quantum simulator is a coveted goal of qu
antum information science. Here \;we provide such a test using quantum
annealing. Specifically\, \;we report on extensive experimental tests
of topological defect \;
\nformation via the one-dimensional tra
nsverse-field Ising model on two \;
\ndifferent D-Wave quantum an
nealing devices. We find that the quantum \;simulator results can inde
ed be explained by the KZM \;for open-system quantum dynamics with pha
se-flip errors\, with certain \; \;quantitative deviations from th
e theory likely caused by factors such as \;random control errors and
transient effects. In addition\, we probe \; \;physics beyond the
KZM by identifying signatures \;of universality in the distribution an
d cumulants of the number of \;kinks and their decay\, and again find
agreement with the quantum \;simulator results. This implies that the
theoretical predictions of the \;generalized KZM theory\, which assume
s isolation from \;the environment\, applies beyond its original scope
to an open system. \;
\n
\nWe support this result by extens
ive numerical computations. To check \;whether an alternative\, classi
cal interpretation of these results is \;possible\, we used the spin-v
ector Monte Carlo model\, \;a candidate classical description of the D
-Wave device. We find that \;the degree of agreement with the experime
ntal data from the D-Wave \;annealing devices is better for the KZM\,
a quantum theory\, than for the \;classical spin-vector Monte Carlo mo
del\, thus favoring \;a quantum description of the device. Our work pr
ovides an experimental \;test of quantum critical dynamics in an open
quantum system\, and paves \;the way to new directions in quantum simu
lation experiments.
\n
\nRef.:
\nYuki Bando\, Yuki Susa\, H
iroki Oshiyama\, Naokazu Shibata\, Masayuki \;
\nOhzeki\, Fernand
o Javier Gó\;mez-Ruiz\, Daniel A. Lidar\, Sei Suzuki\, Adolfo \;
\ndel Campo\, and Hidetoshi Nishimori\, Phys. Rev. Research 2\, 0333
69 (2020)