33,037 research outputs found
Moderate Deviations for the SSEP with a Slow Bond
We consider the one dimensional symmetric simple exclusion process with a
slow bond. In this model, particles cross each bond at rate , except one
particular bond, the slow bond, where the rate is . Above, is the
scaling parameter. This model has been considered in the context of
hydrodynamic limits, fluctuations and large deviations. We investigate moderate
deviations from hydrodynamics and obtain a moderate deviation principle.Comment: 24 page
Critical magnetic field in holographic superconductor in Gauss-Bonnet gravity with Born-Infeld electrodynamics
In the paper using matching method in the probe limit, we investigate some
properties of holographic superconductor in Gauss-Bonnet gravity with
Born-Infeld electrodynamics . We discuss the effects of the Gauss-Bonnet
coupling \a and Born-Infeld parameter on the critical temperature and
condensate. We find that both of \a and make the critical temperature
decrease, which implies the condensate harder to form.
Moreover we study the magnetic effect on holographic superconductor and
obtain that the ratio between the critical magnetic field and the square of the
critical temperature increases from zero as the temperature is lowered below
the critical value , which agrees well with the former results. We also
find the critical magnetic field is indeed affected by Gauss-Bonnet coupling,
but not by Born-Infeld parameter.Comment: 13 pages, 5 figure
Manipulation of electronic and magnetic properties of MC (M=Hf, Nb, Sc, Ta, Ti, V, Zr) monolayer by applying mechanical strains
Tuning the electronic and magnetic properties of a material through strain
engineering is an effective strategy to enhance the performance of electronic
and spintronic devices. Recently synthesized two-dimensional transition metal
carbides MC (M=Hf, Nb, Sc, Ta, Ti, V, Zr), known as MXenes, has aroused
increasingly attentions in nanoelectronic technology due to their unusual
properties. In this paper, first-principles calculations based on density
functional theory are carried out to investigate the electronic and magnetic
properties of MC subjected to biaxial symmetric mechanical strains. At the
strain-free state, all these MXenes exhibit no spontaneous magnetism except for
TiC and ZrC which show a magnetic moment of 1.92 and 1.25 /unit,
respectively. As the tensile strain increases, the magnetic moments of MXenes
are greatly enhanced and a transition from nonmagnetism to ferromagnetism is
observed for those nonmagnetic MXenes at zero strains. The most distinct
transition is found in HfC, in which the magnetic moment is elevated to 1.5
/unit at a strain of 15%. We further show that the magnetic properties
of HfC are attributed to the band shift mainly composed of Hf(5) states.
This strain-tunable magnetism can be utilized to design future spintronics
based on MXenes
Note on Thermodynamics Method of Black Hole/CFT Correspondence
In the paper we further refine the thermodynamics method of black hole/CFT
correspondence. We show that one can derive the central charges of different
holographic pictures directly from the entropy product if it is
mass-independent, for a black hole in the Einstein gravity or the gravity
without diffeomorphism anomaly. For a general black hole in the Einstein
gravity that admits holographic descriptions, we show that the thermodynamics
method and asymptotic symmetry group (ASG) analysis can always give consistent
results in the extreme limit. Furthermore, we discuss the relation between
black hole thermodynamics and the hidden conformal symmetry. We show that the
condition , with being the outer and inner horizon
areas, is the necessary, but not sufficient, condition for a black hole to have
the hidden conformal symmetry. In particular, for the Einstein(-Maxwell)
gravity is just the condition , with
being the outer and inner horizon entropies, which is the condition for the
entropy product being mass-dependent. When there exists the hidden
conformal symmetry in the low-frequency scattering off the generic non-extremal
black hole, it always leads to the same temperatures of dual CFT as the ones
got from the thermodynamics method.Comment: 31 pages, references added, published versio
- β¦