112,001 research outputs found
Geometry defects in Bosonic symmetry protected topological phases
In this paper we focus on the interplay between geometry defects and
topological properties in bosonic symmetry protected topological(SPT) phases.
We start from eight copies of 3D time-reversal() invariant
topological superconductors(TSC) on a crystal lattice. We melt the lattice by
condensation of disclinations and therefore restore the rotation symmetry. Such
disclination condensation procedure confines the fermion and afterwards turns
the system into a 3D boson topological liquid crystal(TCL). The low energy
effective theory of this crystalline-liquid transition contains a topological
term inherited from the geometry axion response in TSC. In addition, we
investigate the interplay between dislocation and superfluid vortex on the
surface of TCL. We demonstrate that the and translation invariant
surface state is a double state with intrinsic
surface topological order. We also look into the exotic behavior of dislocation
in 2D boson SPT state described by an non-linear
-model(NLM) with topological -term. By dressing the
vector with spiral order and gauge the symmetry, the dislocation has
mutual semion statistics with the gauge flux. Further reduce the
NL to the Ising limit, we arrive at the Levin-Gu model with stripy
modulation whose dislocation has nontrivial braiding statistics
Stripe melting, a transition between weak and strong symmetry protected topological phases
For a gapped disordered many-body system with both internal and translation
symmetry, one can define the corresponding weak and strong Symmetry Protected
Topological (SPT) phases. A strong SPT phase is protected by the internal
symmetry only while a weak SPT phase, fabricated by alignment of strong SPT
state in a lower dimension, requires additional discrete translation symmetry
protection. In this paper, we construct a phase transition between weak and
strong SPT phase in strongly interacting boson system. The starting point of
our construction is the superconducting Dirac fermions with pair density
wave(PDW) order in . We first demonstrate that the nodal line of the PDW
contains a boson SPT phase. We further show that melting the PDW stripe
and condensing the nodal line provoke the transition from weak to strong SPT
phase in . The phase transition theory contains an O(4)
non-linear--model(NLM) with topological -term emerging
from the proliferation of domain walls bound to an SPT chain. Similar scheme
also applies to weak-strong SPT transition in other dimensions and predicts
possible phase transition from to topological order
New example of CP violation from search for the permanent electric dipole moment of Cs atoms
Using special capacitors three experiments to search for a permanent electric
dipole moment (EDM) of Cesium atom were completed. The electric susceptibility
xe of Cs vapor varies in direct proportion to the density N, where xe =70 when
N=7.37*1022 m-3! The relationship between xe of Cs vapor and the absolute
temperatures T is xe =B/T, where the slope B=320(k) as polar molecules
H2O(B=1.50(k)). Its capacitance C at different voltage V was measured. The C-V
curve shows that the saturation polarization of Cs vapor has be observed when
the field E=7.4*104V/m. Our measurements give the EDM of an Cs atom :
dCs=2.97*10-29 C.m=1.86*10-8 e.cm. New example of CP (charge conjugation and
parity) violation occurred in Cs atoms. Our results are easy to be repeated
because the details of the experiment are described in the article.Comment: 7 pages, 7 figures,1 tabl
PI-REC: Progressive Image Reconstruction Network With Edge and Color Domain
We propose a universal image reconstruction method to represent detailed
images purely from binary sparse edge and flat color domain. Inspired by the
procedures of painting, our framework, based on generative adversarial network,
consists of three phases: Imitation Phase aims at initializing networks,
followed by Generating Phase to reconstruct preliminary images. Moreover,
Refinement Phase is utilized to fine-tune preliminary images into final outputs
with details. This framework allows our model generating abundant high
frequency details from sparse input information. We also explore the defects of
disentangling style latent space implicitly from images, and demonstrate that
explicit color domain in our model performs better on controllability and
interpretability. In our experiments, we achieve outstanding results on
reconstructing realistic images and translating hand drawn drafts into
satisfactory paintings. Besides, within the domain of edge-to-image
translation, our model PI-REC outperforms existing state-of-the-art methods on
evaluations of realism and accuracy, both quantitatively and qualitatively.Comment: 15 pages, 13 figure
Two puzzling problems in explanation of the linear Stark effect of hydrogen atom and space quantization of the dipole moment
The linear Stark effect for the first excited state of the hydrogen atom
shows that, in the unperturbed states, the atom has a permanent electric dipole
moment (EDM) of magnitude 3eao (ao is Bohr radius). The EDM is not induce by
the external field but is inherent behavior of the atom. But the calculation of
quantum mechanics tells us that unperturbed states of hydrogen atom have no
EDM! In the effect, two of four states have no energy shift. What are the EDM
of the hydrogen atoms in the two states? Quantum mechanics can not answer the
problem. The statement that the EDM of the two states is perpendicular to the
field only comes from guesses in quantum mechanics. The two problems had
puzzled physicists for more than 80 years. By introducing a new parameter this
article gives a satisfactory explanation for the effect. Our calculation
discovered that, in the unperturbed states, the atoms not only have EDM with
3eao but also can have only three directions of quantization! It is an entirely
unexpected discovery. This research is a vital clue that not all is well with
quantum mechanics. We prophesy that hydrogen-like atoms, such as K, Rb and Cs
atom etc, may have large EDM of the order of magnitude eao in their ground
state (see arXiv:0809.4767, arXiv:0810.0770 and arXiv:0810.2026).Comment: 6 pages, 2 table
Clear evidence of charge conjugation and parity violation in K atoms from atomic permanent electric dipole moment experiments
Quantum mechanics thinks that atoms do not have permanent electric dipole
moment (EDM) because of their spherical symmetry. Therefore, there is no polar
atom in nature except for polar molecules. The electric susceptibility Xe
caused by the orientation of polar substances is inversely proportional to the
absolute temperature T while the induced susceptibility of atoms is temperature
independent. This difference in temperature dependence offers a means of
separating the polar and non-polar substances experimentally. Using special
capacitor our experiments discovered that the relationship between Xe of
Potassium atom and T is just Xe=B/T, where the slope B is approximately 283(K)
as polar molecules, but appears to be disordered using the traditional
capacitor. Its capacitance C at different voltage V was measured. The C-V curve
shows that the saturation polarization of K vapor has be observed when E more
than 105V/m and nearly all K atoms (over 98.9 per cent) are lined up with the
field! The ground state neutral K atom is polar atom with a large EDM: dK more
than 2.3*10-9e.cm.The results gave clear evidence for CP (charge conjugation
and parity) violation in K atoms. If K atom has a large EDM, why the linear
Stark effect has not been observed? The article discussed the question
thoroughly. Our results are easy to be repeated because the details of the
experiment are described in the article.Comment: 7 pages, 6 figures, 2 table
Injectable Spontaneous Generation of Tremendous Self-Fueled Liquid Metal Droplet Motors in a Moment
Micro motors that could run in liquid environment is very important for a
variety of practices such as serving as pipeline robot, soft machine, drug
delivery, or microfluidics system etc. However, fabrication of such tiny motors
is generally rather time and cost consumptive and has been a tough issue due to
involve too many complicated procedures and tools. Here, we show a
straightforward injectable way for spontaneously generating autonomously
running soft motors in large quantity. A basic fabrication strategy thus
enabled is established and illustrated. It was found that, injecting the GaIn
alloy pre-fueled with aluminum into electrolyte would automatically split in
seconds into tremendous droplet motors swiftly running here and there. The
driving force originated from the galvanic cell reaction among alloy, aluminum
and surrounding electrolyte which offers interior electricity and hydrogen gas
as motion power. This finding opens the possibility to develop injectable
tiny-robots, droplet machines or microfluidic elements. It also raised
important scientific issues regarding characterizing the complicated fluid
mechanics stimulated by the quick running of the soft metal droplet and the
gases it generated during the traveling.Comment: 12 pages, 5 figure
Branching random walk in random environment with random absorption wall
We consider the branching random walk in random environment with a random
absorption wall. When we add this barrier, we discuss some topics related to
the survival probability. We assume that the random environment is i.i.d.,
is a particular i.i.d. random walk depend on the random environment
. Let the random barrier function (the random absorption wall) is
where present the generation. We show
that there exists a critical value such that if
, the survival probability is positive almost surly
and if ,the survival probability is zero almost
surely. Moreover, if we denote is the total populations in -th
generation in the new system (with barrier),under some conditions, we show
will converges to a negative
constant almost surely if .Comment: 18 page
Relative Gromov-Witten invariants and the enumerative meaning of mirror maps for toric Calabi-Yau orbifolds
We provide an enumerative meaning of the mirror maps for toric Calabi-Yau
orbifolds in terms of relative Gromov-Witten invariants of the toric
compactifications. As a consequence, we obtain an equality between relative
Gromov-Witten invariants and open Gromov-Witten invariants. Therefore, the
instanton corrected mirrors for toric Calabi-Yau orbifolds can be constructed
using relative Gromov-Witten invariants.Comment: 35 pages. Revised according to the referee's comments. To appear in
Transactions of the American Mathematical Societ
Can We Reach the Scale of New Physics Behind the Anomalies?
Indirect signs of new physics beyond the Standard Model may be appearing in
decays. If confirmed, the title question will be of
paramount importance in determining the strategy for future colliders. We
answer it by estimating the sensitivity to minimal, anomaly-compatible
and leptoquark models at the high luminosity LHC, 27 TeV HE-LHC, and
100 TeV FCC-hh; this conservative analysis outlines an upper bound on the
available parameter space and the conditions for a reasonable guarantee of
direct discovery.Comment: 4 pages, 4 figures. Contribution to the proceedings of the 53rd
Rencontres de Morion
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