Physical Review Letters,
Journal Year:
2020,
Volume and Issue:
125(11)
Published: Sept. 9, 2020
Solids
built
out
of
active
components
can
exhibit
nonreciprocal
elastic
coefficients
that
give
rise
to
non-Hermitian
wave
phenomena.
Here,
we
investigate
effects
present
at
the
boundary
two-dimensional
media
obeying
two
general
assumptions:
their
microscopic
forces
conserve
linear
momentum
and
arise
only
from
static
deformations.
Using
continuum
equations,
demonstrate
existence
skin
effect
in
which
hosts
an
extensive
number
localized
modes.
Furthermore,
lattice
models
reveal
topological
transitions
mediated
by
exceptional
rings
driven
activity
level
individual
bonds.
Reviews of Modern Physics,
Journal Year:
2021,
Volume and Issue:
93(1)
Published: Feb. 24, 2021
Quantum
systems
that
are
coupled
to
an
external
bath
can
often
be
described
in
terms
of
a
non-Hermitian
effective
Hamiltonian.
In
isolated
with
Hermitian
Hamiltonians,
topological
aspects
the
band
structure,
and
resulting
phases,
have
been
interest.
The
combination
two
concepts,
i.e.,
properties
open
systems,
leads
qualitatively
new
effects.
This
review
provides
introduction
these
quantum
mechanical
concepts
their
classical
analogs,
discusses
number
applications
ranging
from
metamaterials
dissipative
cold-atom
systems.
Physical Review Letters,
Journal Year:
2019,
Volume and Issue:
123(17)
Published: Oct. 21, 2019
One
of
the
unique
features
non-Hermitian
Hamiltonians
is
skin
effect,
namely,
that
eigenstates
are
exponentially
localized
at
boundary
system.
For
open
quantum
systems,
a
short-time
evolution
can
often
be
well
described
by
effective
Hamiltonians,
while
long-time
dynamics
calls
for
Lindblad
master
equations,
in
which
Liouvillian
superoperators
generate
time
evolution.
In
this
Letter,
we
find
exhibit
and
uncover
its
unexpected
physical
consequences.
It
shown
effect
dramatically
shapes
dynamics,
such
damping
class
systems
algebraic
under
periodic
conditions
but
exponential
conditions.
Moreover,
non-Bloch
bands
cause
chiral
with
sharp
wave
front.
These
phenomena
beyond
Hamiltonians;
instead,
they
belong
to
physics
full-fledged
dynamics.
Proceedings of the National Academy of Sciences,
Journal Year:
2020,
Volume and Issue:
117(47), P. 29561 - 29568
Published: Nov. 9, 2020
Topological
edge
modes
are
excitations
that
localized
at
the
materials'
edges
and
yet
characterized
by
a
topological
invariant
defined
in
bulk.
Such
bulk-edge
correspondence
has
enabled
creation
of
robust
electronic,
electromagnetic
mechanical
transport
properties
across
wide
range
systems,
from
cold
atoms
to
metamaterials,
active
matter
geophysical
flows.
Recently,
advent
non-Hermitian
systems---wherein
energy
is
not
conserved---has
sparked
considerable
theoretical
advances.
In
particular,
novel
phases
can
only
exist
systems
have
been
introduced.
However,
whether
such
be
experimentally
observed,
what
their
are,
remained
open
questions.
Here,
we
identify
observe
form
for
particular
phase.
We
find
change
bulk
leads
mode
localisation
together
with
peculiar
purely
properties.
Using
quantum-to-classical
analogy,
create
metamaterial
non-reciprocal
interactions,
which
predicted
correspondence,
demonstrating
its
robustness.
Our
results
new
avenues
field
topology
manipulating
waves
unprecedented
fashions.
Physical Review Letters,
Journal Year:
2020,
Volume and Issue:
125(22)
Published: Nov. 24, 2020
We
provide
a
systematic
and
self-consistent
method
to
calculate
the
generalized
Brillouin
zone
(GBZ)
analytically
in
one-dimensional
non-Hermitian
systems,
which
helps
us
understand
bulk-boundary
correspondence.
In
general,
$n$-band
Hamiltonian
is
constituted
by
$n$
distinct
sub-GBZs,
each
of
piecewise
analytic
closed
loop.
Based
on
concept
resultant,
we
can
show
that
all
properties
GBZ
be
characterized
an
algebraic
equation,
solution
complex
plane
dubbed
as
auxiliary
(aGBZ).
also
obtain
from
aGBZ.
Two
physical
applications
are
discussed.
Our
provides
approach
spectral
problem
open
boundary
systems
thermodynamic
limit.
Physical Review Research,
Journal Year:
2019,
Volume and Issue:
1(2)
Published: Sept. 11, 2019
This
paper
uncovers
a
bulk
probing
method
to
catch
physical
effects
hindered
in
topological
non-Hermitian
crystals.
The
is
based
on
Lyapunov
exponent
calculation
of
quantum
walker
the
lattice
and
can
reveal
non-Bloch
phase
transitions,
skin
effect
breakdown
bulk-boundary
correspondence.
Physical Review Letters,
Journal Year:
2020,
Volume and Issue:
125(18)
Published: Oct. 29, 2020
We
introduce
and
study
a
novel
class
of
sensors
whose
sensitivity
grows
exponentially
with
the
size
device.
Remarkably,
this
drastic
enhancement
does
not
rely
on
any
fine-tuning,
but
is
found
to
be
stable
phenomenon
immune
local
perturbations.
Specifically,
physical
mechanism
behind
striking
intimately
connected
anomalous
boundary
conditions
observed
in
non-Hermitian
topological
systems.
outline
concrete
platforms
for
practical
implementation
these
ranging
from
classical
metamaterials
synthetic
quantum
materials.
eLight,
Journal Year:
2021,
Volume and Issue:
1(1)
Published: June 7, 2021
Abstract
Let
there
be
light
–to
change
the
world
we
want
to
be!
Over
past
several
decades,
and
ever
since
birth
of
first
laser,
mankind
has
witnessed
development
science
light,
as
light-based
technologies
have
revolutionarily
changed
our
lives.
Needless
say,
photonics
now
penetrated
into
many
aspects
technology,
turning
an
important
dynamically
changing
field
increasing
interdisciplinary
interest.
In
this
inaugural
issue
eLight
,
highlight
a
few
emerging
trends
in
that
think
are
likely
major
impact
at
least
upcoming
decade,
spanning
from
integrated
quantum
computing,
through
topological/non-Hermitian
topological
insulator
lasers,
AI-empowered
nanophotonics
photonic
machine
learning.
This
Perspective
is
by
no
means
attempt
summarize
all
latest
advances
photonics,
yet
wish
subjective
vision
could
fuel
inspiration
foster
excitement
scientific
research
especially
for
young
researchers
who
love
.
The
non-Hermitian
skin
effect
is
a
unique
feature
of
systems,
in
which
an
extensive
number
boundary
modes
appear
under
the
open
conditions.
Here,
we
discover
higher-order
counterparts
that
exhibit
new
physics.
In
two-dimensional
systems
with
system
size
$L
\times
L$,
while
conventional
(first-order)
accompanies
$O\,(
L^{2}
)$
modes,
second-order
L
corner
modes.
This
also
contrasts
Hermitian
topological
insulators,
only
1
zero
appear.
Moreover,
for
third-order
three
dimensions,
from
all
L^{3}
We
demonstrate
originates
intrinsic
topology
protected
by
spatial
symmetry.
show
it
modification
non-Bloch
band
theory
higher
dimensions.