Speaker
Pierre-Nicholas
Roy
|
Department
of
Chemistry,
University
of
Waterloo
http://www.science.uwaterloo.ca/~pnroy/
Title
Quantum Molecular Dynamics
Abstract
Molecular assemblies
are
often
described
using
classical
concepts
and
simulated
using Newtonian
dynamics
or
Classical
Monte
Carlo
methods.
At
low
temperatures,
this classical description
fails
to
capture
the
nature
of
the
dynamics
of
molecules, and
a
quantum
description
is
required
in
order
to
explain
and
predict
the outcome
of
experiments.
We
will
present mathematical
formalisms
and
simulation algorithms
for
the
study
of
nano-confined
systems.
For
instance,
the
Feynman path
integral
formulation
of
quantum
statistical
mechanics
is
a very
powerful tool
that
is
amenable
to
large-scale
simulations
[1].
We
will
show
how
path integral
simulations
can
be
used
to
predict
the
properties
of
molecular
rotors trapped
in superfluid
helium
and
hydrogen
clusters
[2].
We
will
demonstrate that
microscopic
Andronikashvili
experiments
can
be
viewed
as
a
measurement
of superfluidity
in
a
quantum mechanical
frame
of
reference
[6].
Issues
such
as quantization
in
curved
spaces
will
be
addressed.
The
estimation
of
entanglement measures
in
Quantum
Monte
Carlo
simulations
will be
discussed
[3]
and
applied to
confined
molecular
rotors
[7].
Such
systems
can
be
realized
using
molecules confined
in
endohedral
fullerene
materials
such
as
H2O@C60
and HF@C60
in peapods
assemblies.
These
systems
will
be
used
as
a
platform
to
assess
the relative
merits
of
many-
body
wavefunction
representations
based
on
path integrals
[7], truncated
product
bases
[4],
matrix
product
states
[5],
and other
possibilities
such
as
Restricted
Boltzmann
Machines
[8].
[1]
T.
Zeng, N.
Blinov,
K.
Bishop,
G.
Guillon,
H.
Li,
and
P.-N.
Roy,
Comp.
Phys.
Comm.
204, 170
(2016).
[2]
T.
Zeng and
P.-N.
Roy,
Rep.
Prog.
Phys.
77,
046601
(2014).
[3]
C.
M. Herdman,
P.-N.
Roy,
R.
G.
Melko,
A.
Del
Maestro,
Nature
Physics
13,
556
(2017).
[4]
T Halverson,
D.
Iouchtchenko,
and
P.-N.
Roy,
J.
Chem.
Phys.
148,
074112
(2018).
[5]
D. Iouchtchenko
and
P.-N.
Roy,
J.
Chem.
Phys.
148,
134115
(2018).
[6]
H.
Li
and X.-L.
Zhang
and
T.
Zeng
and
R.
J.
Le
Roy
and
P.-N.
Roy,
Phys.
Rev.
Lett.
123 093001
(2019)
[7]
T.
Sahoo and
D.
Iouchtchenko
and
C.
Herdman
and
P.-N.
Roy,
J.
Chem.
Phys.
152
184113 (2020)
[8]
I.
J.
De
Vlugt
and
D.
Iouchtchenko
and
E.
Merali
and
P.-N.
Roy
and R.
G. Melko,
Phys.
Rev.
B
102
035108
(2020)