We
propose
an
alternative
mechanism
for
the
quantum
anomalous
Hall
(QAH)
effect
in
$AB$
stacked
$\mathrm{Mo}{\mathrm{Te}}_{2}/\mathrm{W}{\mathrm{Se}}_{2}$
system.
Based
on
observation
that
interlayer
tunneling
is
suppressed
stacking,
we
consider
a
model
with
two
layers
coupled
through
Coulomb
interaction.
The
moir\'e
lattices
of
are
shifted
to
form
honeycomb
lattice.
Initially,
system
layer-polarized
Mott
insulator
at
${\ensuremath{\nu}}_{T}=1$.
But
displacement
field,
equal
number
holes
and
electrons
doped
into
layers,
forming
exciton
condensation.
Through
mean
field
theory,
find
$p\ifmmode\pm\else\textpm\fi{}ip$
condensation
certain
parameter
regime,
which
leads
Chern
$\text{C}=\ifmmode\pm\else\textpm\fi{}1$.
valleys
polarized
due
kinetic
energy
instead
interaction,
but
polarization
can
be
either
same
or
opposite.
In
particular,
intervalley-coherent
(IVC)
phase
possible,
agreement
recent
magnetic
circular
dichroism
(MCD)
measurement.
Our
work
opens
another
direction
search
topologically
nontrivial
excitonic
high
angular
momentum
pairing
symmetry.
Science,
Journal Year:
2023,
Volume and Issue:
379(6639)
Published: March 31, 2023
Moiré
superlattices,
the
artificial
quantum
materials,
have
provided
a
wide
range
of
possibilities
for
exploration
completely
new
physics
and
device
architectures.
In
this
Review,
we
focus
on
recent
progress
emerging
moiré
photonics
optoelectronics,
including
but
not
limited
to
excitons,
trions,
polaritons;
resonantly
hybridized
excitons;
reconstructed
collective
excitations;
strong
mid-
far-infrared
photoresponses;
terahertz
single-photon
detection;
symmetry-breaking
optoelectronics.
We
also
discuss
future
opportunities
research
directions
in
field,
such
as
developing
advanced
techniques
probe
emergent
optoelectronics
an
individual
supercell;
exploring
ferroelectric,
magnetic,
multiferroic
systems;
using
external
degrees
freedom
engineer
properties
exciting
potential
technological
innovations.
Science,
Journal Year:
2023,
Volume and Issue:
380(6647), P. 860 - 864
Published: May 11, 2023
A
panoply
of
unconventional
electronic
states
has
been
observed
in
moiré
superlattices.
Engineering
similar
bosonic
phases
remains,
however,
largely
unexplored.
We
report
the
observation
a
correlated
insulator
tungsten
diselenide/tungsten
disulfide
(WSe2/WS2)
superlattices
composed
excitons,
that
is,
tightly
bound
electron-hole
pairs.
develop
pump
probe
spectroscopy
method
we
use
to
observe
an
exciton
incompressible
state
at
filling
νex
=
1
and
charge
neutrality,
indicating
excitons.
With
varying
density,
continuously
transitions
into
electron
νe
1,
suggesting
mixed
insulating
between
two
limits.
Our
studies
establish
semiconducting
as
intriguing
platform
for
engineering
phases.
Physical Review Letters,
Journal Year:
2022,
Volume and Issue:
129(5)
Published: July 28, 2022
We
present
a
theory
on
the
quantum
phase
diagram
of
AB-stacked
MoTe$_2$/WSe$_2$
using
self-consistent
Hartree-Fock
calculation
performed
in
plane-wave
basis,
motivated
by
observation
topological
states
this
system.
At
filling
factor
$\nu=2$
(two
holes
per
moir\'e
unit
cell),
Coulomb
interaction
can
stabilize
$\mathbb{Z}_2$
insulator
opening
charge
gap.
$\nu=1$,
induces
three
classes
competing
states,
spin
density
wave
an
in-plane
ferromagnetic
state,
and
valley
polarized
which
undergo
first-order
transitions
tuned
out-of-plane
displacement
field.
The
state
becomes
Chern
for
certain
fields.
Moreover,
we
predict
forming
honeycomb
lattice
with
ferromagnetism
at
$\nu=2/3$.
Future
directions
versatile
system
hosting
rich
set
phases
are
discussed.
