Chinese Physics Letters,
Год журнала:
2023,
Номер
40(6), С. 067801 - 067801
Опубликована: Май 1, 2023
Optical
fine-tunable
layer-hybridized
Moiré
excitons
are
highly
in
demand
for
emerging
many-body
states
two-dimensional
semiconductors.
We
report
naturally
confined
bright
with
long
lifetimes
twisted
hexagonal
GaTe
bilayers,
using
ab
initio
perturbation
theory
and
the
Bethe–Salpeter
equation.
Due
to
hybridization
of
electrons
holes
between
layers,
which
enhances
brightness
excitons,
bilayer
system
becomes
attractive
optical
applications.
find
that
both
R
H-type
stacking
superlattices,
more
than
200
meV
lateral
quantum
confinements
occur
on
exciton
energies,
results
two
scenarios:
(1)
The
ground
state
X
A
found
be
trapped
at
high-symmetry
points,
opposite
electric
dipoles
R-stacking
supercell,
forming
a
honeycomb
superlattice
nearest-neighbor
dipolar
attraction.
(2)
For
H-stacking
case,
is
only
one
point
exhibiting
triangular
superlattice.
Our
suggest
h-GaTe
promising
systems
excitonic
devices
provide
an
ideal
platform
realizing
strong
correlated
Bose–Hubbard
physics.
Nano Letters,
Год журнала:
2024,
Номер
24(51), С. 16391 - 16399
Опубликована: Дек. 12, 2024
Twisted
van
der
Waals
heterostructures
have
led
to
emerging
layer-dependent
correlated
physics
in
moiré
potentials.
While
optoelectronic
controls
over
interlayer
electronic
coupling
been
reported,
the
concomitant
vibration
has
not
yet
controlled.
Here,
we
report
experimental
evidence
of
ultrafast
optical
control
amplitude
and
oscillation
period
breathing
phonons
WSe2/WS2
heterobilayers.
Femtosecond
excitation
above
Mott
density
gate-tuned
devices
shows
as
large
10%
changes
stiffening
softening
coherent
phonons.
A
theoretical
model,
incorporating
both
Buckingham
Hartree
energies,
is
presented
elucidate
impact
charge-separated
carriers
generated
by
photoexcitation
on
phonon
dynamics.
This
work,
therefore,
provides
insights
for
extending
engineering
into
systems.
Proceedings of the National Academy of Sciences,
Год журнала:
2024,
Номер
122(1)
Опубликована: Дек. 31, 2024
Moiré
excitons
and
moiré
magnetism
are
essential
to
semiconducting
van
der
Waals
magnets.
In
this
work,
we
perform
a
comprehensive
first-principles
study
elucidate
the
interplay
of
electronic
excitation
in
twisted
magnetic
CrSBr
bilayers.
We
predict
twist-induced
quantum
phase
transition
for
interlayer
coupling
estimate
critical
twist
angle
below
which
with
mixed
ferromagnetic
antiferromagnetic
domains
could
emerge.
Localized
one-dimensional
stable
if
is
become
unstable
turns
antiferromagnetic.
Exciton
energy
modulation
by
magnons
estimated
dependence
exciton
oscillator
strength
on
analyzed.
An
orthogonally
bilayer
revealed
exhibit
layer-dependent,
anisotropic
optical
transitions.
Electric
field
shown
induce
net
moments
excitons,
endowing
them
exceedingly
long
lifetimes.
Our
work
lays
foundation
using
bilayers
spintronic,
optoelectronic,
information
applications.
Physical Review Letters,
Год журнала:
2023,
Номер
131(23)
Опубликована: Дек. 5, 2023
It
is
well
known
that
two-dimensional
(2D)
bosons
in
homogeneous
space
cannot
undergo
real
Bose-Einstein
condensation,
and
the
superfluid
to
normal
phase
transition
Berezinskii-Kosterlitz-Thouless
(BKT)
type,
associated
with
vortex--antivortex
pair
unbinding.
Here
we
point
out
a
2D
bosonic
system
whose
low
energy
physics
goes
beyond
conventional
paradigm
of
bosons,
i.e.,
intralayer
excitons
monolayer
metal
dichalcogenides.
With
intrinsic
valley-orbit
coupling
valley
Zeeman
energy,
exciton
dispersion
becomes
linear
at
small
momentum,
giving
rise
series
novel
features.
The
critical
temperature
condensation
these
nonzero,
suggesting
true
long-range
order
system.
Goldstone
mode
long
wavelength
has
form
$ϵ(\mathbit{q})\ensuremath{\sim}\sqrt{q}$,
contrast
phonon
spectrum.
vortex
deviates
from
usual
logarithmic
respect
size,
but
instead
an
additional
term.
Superfluid
no
longer
BKT
type
for
size
characteristic
scale,
without
discontinuous
jump
density.
recent
experimental
progress
on
fluid
thermal
equilibrium
semiconductors,
our
work
points
experimentally
accessible
search
unconventional
superfluids
paradigm.
Chinese Physics Letters,
Год журнала:
2023,
Номер
40(6), С. 067801 - 067801
Опубликована: Май 1, 2023
Optical
fine-tunable
layer-hybridized
Moiré
excitons
are
highly
in
demand
for
emerging
many-body
states
two-dimensional
semiconductors.
We
report
naturally
confined
bright
with
long
lifetimes
twisted
hexagonal
GaTe
bilayers,
using
ab
initio
perturbation
theory
and
the
Bethe–Salpeter
equation.
Due
to
hybridization
of
electrons
holes
between
layers,
which
enhances
brightness
excitons,
bilayer
system
becomes
attractive
optical
applications.
find
that
both
R
H-type
stacking
superlattices,
more
than
200
meV
lateral
quantum
confinements
occur
on
exciton
energies,
results
two
scenarios:
(1)
The
ground
state
X
A
found
be
trapped
at
high-symmetry
points,
opposite
electric
dipoles
R-stacking
supercell,
forming
a
honeycomb
superlattice
nearest-neighbor
dipolar
attraction.
(2)
For
H-stacking
case,
is
only
one
point
exhibiting
triangular
superlattice.
Our
suggest
h-GaTe
promising
systems
excitonic
devices
provide
an
ideal
platform
realizing
strong
correlated
Bose–Hubbard
physics.
