3,789 research outputs found
A sufficient Entanglement Criterion Based On Quantum Fisher Information and Variance
We derive criterion in the form of inequality based on quantum Fisher
information and quantum variance to detect multipartite entanglement. It can be
regarded as complementary of the well-established PPT criterion in the sense
that it can also detect bound entangled states. The inequality is motivated by
Y.Akbari-Kourbolagh [Phys. Rev A. 99, 012304 (2019)] which introduced
a multipartite entanglement criterion based on quantum Fisher information. Our
criterion is experimentally measurable for detecting any -qudit pure state
mixed with white noisy. We take several examples to illustrate that our
criterion has good performance for detecting certain entangled states.Comment: 11 pages, 1 figur
Ordered valence bond states in symmetric two-dimensional spin-orbital systems
We consider a superexchange Hamiltonian, , which describes
systems with orbital degeneracy and strong electron-phonon coupling in the
limit of large on-site repulsion. In an SU(4) Schwinger boson representation, a
reduced spin-orbital interaction is derived {\it exactly}, and a mean field
theory has been developed by introducing a symmetric valence bond pairing order
parameter. In one dimension, a spin-orbital liquid state with a finite gap is
obtained. On a two-dimensional square lattice a novel type of spin-orbital
ferromagnetically ordered state appears, while spin and orbital are
antiferromagnetic. Moreover, an important relation has been found, relating the
spin and orbital correlation functions to the combined spin-orbital ones.Comment: four pages in Revtex, no figures, accepted for publication in
Physical Review Letter
Transfer of Gravitational Information through a Quantum Channel
Gravitational information is incorporated into an atomic state by correlation
of the internal and external degrees of freedom of the atom, in the present
study of the atomic interferometer. Thus it is difficult to transfer
information by using a standard teleportation scheme. In this paper, we propose
a novel scheme for the transfer of gravitational information through a quantum
channel provided by the entangled atomic state. Significantly, the existence of
a quantum channel suppresses phase noise, improving the sensitivity of the
atomic interferometer. Thus our proposal provides novel readout mechanism for
the interferometer with an improved signal-to-noise ratio
Simple non-Abelian extensions of the standard model gauge group and the diboson excesses at the LHC
The ATLAS collaboration reported excesses at around 2 TeV in the di-boson
production decaying into hadronic final states. We consider the possibility of
explaining the excesses with extra gauge bosons in two simple non-Abelian
extensions of the Standard Model. One is the so-called models with a
symmetry structure of and the other is
the models with an extended symmetry of . The and bosons emerge after the electroweak symmetry is
spontaneously broken. Two patterns of symmetry breaking in the models
are considered in this work: one is , the other is . The symmetry breaking of the model is
. We perform a global
analysis of and phenomenology in ten new physics models,
including all the channels of decay. Our study shows that
the leptonic mode and the dijet mode of decays impose a
very stringent bound on the parameter space in several new physics models. Such
tight bounds provide a useful guide for building new physics models to address
on the diboson anomalies. We also note that the Left-Right and Lepton-Phobic
models can explain the excess if the deviation in
the pair around 2~TeV were confirmed to be a fluctuation of the SM
backgrounds.Comment: Publish version; title changed as suggested by journal Edito
Resolving the Degeneracy in Single Higgs Production with Higgs Pair Production
The Higgs boson production can be affected by several anomalous couplings,
e.g. and anomalous couplings. Precise measurement of
production yields two degenerate parameter spaces of and ; one
parameter space exhibits the SM limit while the other does not. Such a
degeneracy could be resolved by Higgs boson pair production. In this work we
adapt the strategy suggested by the ATLAS collaboration to explore the
potential of distinguishing the degeneracy at the 14 TeV LHC. If the
anomalous coupling is induced only by the operator , then the non-SM-like band could be excluded with an integrated luminosity
of . Making use of the fact that the Higgs boson pair
is mainly produced through an -wave scattering, we propose an analytical
function to describe the fraction of signal events surviving a series of
experimental cuts for a given invariant mass of Higgs boson pair. The function
is model independent and can be applied to estimate the discovery potential of
various NP models
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