GaSI: A Wide-Gap Non-centrosymmetric Helical Crystal
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(33), С. 22881 - 22886
Опубликована: Июль 22, 2024
The
complex
non-centrosymmetric
and
chiral
nature
of
helical
structures
endow
materials
that
possess
such
motifs
with
unusual
properties.
However,
despite
their
ubiquity
in
biological
organic
systems,
there
is
a
severe
lack
inorganic
crystals
display
helicity
extended
lattices,
where
these
properties
are
expected
to
be
most
pronounced.
Here,
we
report
new
structure,
gallium
sulfur
iodide
(GaSI),
within
the
exfoliable
class
III–VI–VII
(1:1:1)
one-dimensional
(1D)
van
der
Waals
(vdW)
crystals.
Through
detailed
structural
analyses,
including
single-crystal
X-ray
diffraction,
electron
microscopy,
density
functional
theory
(DFT),
elucidate
apparent
noncrystallographic
screw
axis
first
example
an
atomic
scale
structure
bearing
"squircular"
cross-section
GaSI.
Crystallizing
P4̅
space
group,
found
GaSI
exhibit
pronounced
second-harmonic
generation.
From
diffuse
reflectance
spectroscopy,
displays
sizeable
bandgap
3.69
eV,
owing
tostrong
covalent
interactions
arising
from
smaller
atoms
helix
core.
These
results
position
as
promising
nonlinear
optical
material
across
broad
window.
Язык: Английский
Structural and angle-resolved optical and vibrational properties of chiral trivial insulator InSeI
Applied Physics Reviews,
Год журнала:
2024,
Номер
11(4)
Опубликована: Ноя. 25, 2024
Chiral
materials,
known
for
their
unique
structural
and
quantum
properties,
have
garnered
significant
interest,
with
InSeI
emerging
as
a
promising
chiral
topologically
trivial
insulator.
In
this
study,
we
introduce
scalable
Bridgman
crystal
growth
technique
to
synthesize
large,
environmentally
stable
single
crystals
of
InSeI,
achieving
centimeter-sized
superior
quality.
Notably,
work
marks
the
first
report
photoluminescence
(PL)
emission
from
exfoliated
chains,
alongside
detailed
exploration
polarization-dependent
optical
phononic
properties.
Our
Bridgman-grown
exhibit
excellent
integrity,
enhanced
exfoliation
characteristics,
increased
resistance
light-induced
degradation
compared
those
produced
by
traditional
solid-state
methods.
A
microscopy
analysis
confirms
distinct
structure
in
situ
nanometer
spatial
resolution
electron
energy
loss
spectroscopy
measurements
establish
bandgap
2.08
eV,
consistent
cryogenic
PL
peak.
Angle-resolved
Raman
spectroscopy,
combined
calculated
vibrational
identifies
five
frequency
regions
modes,
predominantly
associated
In-,
In-I,
In-Se-I,
Se-atomic
motions,
intensity
variations
under
different
polarization
orientations.
This
study
not
only
offers
practical
method
synthesizing
high-quality
but
also
provides
comprehensive
experimental
insights
into
its
significantly
advancing
understanding
material
systems.
Язык: Английский
Chirality-Induced Majorana Zero Modes and Majorana Polarization
ACS Nano,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 5, 2024
Realizing
Majorana
Fermions
has
always
been
regarded
as
a
crucial
and
formidable
task
in
topological
superconductors.
In
this
work,
we
report
physical
mechanism
material
platform
for
realizing
zero
modes
(MZMs).
This
consists
of
open
circular
helix
molecule
(CHM)
proximity
coupled
with
an
s-wave
superconductor
(under
external
magnetic
field)
or
interconnected-CHM
chain
phase-bias
superconducting
heterostructure
(without
any
field).
MZMs
generated
here
are
tightly
associated
the
structural
chirality
CHMs.
Notably,
left-
right-handedness
results
completely
opposite
polarization
(MP),
leading
us
to
refer
phenomenon
chirality-induced
MP
(CIMP).
Importantly,
local
CIMP
is
closely
linked
spin
polarization,
providing
effective
way
regulate
through
selectivity
(CISS)
effect.
Furthermore,
can
be
detected
by
spin-polarized
current
measurements
related
CISS
chiral
materials.
Язык: Английский