The reduction of the closest disentangled states

We study the closest disentangled state to a given entangled state in any system (multi-party with any dimension). We obtain the set of equations the closest disentangled state must satisfy, and show that its reduction is strongly related to the extremal condition of the local filtering on each party. Although the equations we obtain are not still tractable, we find some sufficient conditions for which the closest disentangled state has the same reduction as the given entangled state. Further, we suggest a prescription to obtain a tight upper bound of the relative entropy of entanglement in two-qubit systems.Comment: a crucial error was correcte

Probing non-Abelian statistics of Majorana fermions in ultracold atomic superfluid

We propose an experiment to directly probe the non-Abelian statistics of Majorana fermions by braiding them in an s-wave superfluid of ultracold atoms. We show different orders of braiding operations give orthogonal output states that can be distinguished through Raman spectroscopy. Realization of Majorana bound states in an s-wave superfluid requires strong spin-orbital coupling and a controllable Zeeman field in the perpendicular direction. We present a simple laser configuration to generate the artificial spin-orbital coupling and the required Zeeman field in the dark state subspace.Comment: 4 pages; Add detailed discussion of feasibility of the scheme;add ref

πΔΔ\pi \Delta\Delta coupling constant

We calculate the $\pi \Delta\Delta$ coupling $g_{\pi^0\Delta^{++}\Delta^{++}}$ using light cone QCD sum rule. Our result is $g_{\pi^0\Delta^{++}\Delta^{++}}=(11.8\pm 2.0)$.Comment: RevTex, 5 pages + 1 PS figur

The impact of COVID-19 on destination visit intention and local food consumption

Purpose: This paper aims to investigate the relationships between motivation and intention to consume local food and between intention to consume local food and intention to visit the destination of that food's origin while examining the moderating effect of risk perception associated with coronavirus disease 2019 (COVID-19). Design/methodology/approach: Data were collected from two samples of potential Chinese tourists in the contexts of Italian and Thai food. Data obtained from 264 Chinese respondents for Italian food and 277 Chinese respondents for Thai food were analyzed. Partial least squares structural equation modeling was utilized to test the research model. Findings: The results indicate that, while motivational factors such as cultural experience, novelty and sensory appeal influence potential Chinese tourists' intention to consume Italian food, motivational factors such as cultural experience, health concern, novelty and sensory appeal influence tourists' intention to consume Thai food. The authors found that intention to consume local food positively influences tourists' intention to visit both destinations (Italy and Thailand). Moreover, tourists' risk perceptions of COVID-19 negatively moderate the effect of cultural experience and novelty on the intention to consume Italian food. Regarding the intention to consume Thai food, the authors found that tourists' risk perceptions have a diminishing effect on all motivational factors. Originality/value: This pioneering study examines the role of COVID-19-related risk perception on the relationships among motivation of local food consumption, intention of local food consumption and destination visit intention in the context of two destination countries. It reveals cross-country differences of the negative effect pertaining to the risk perceptions of COVID-19, which has important implications for international destination marketing

Temperature dependence of the conductivity of the electronic crystal

We study the temperature dependence of the conductivity of the 2D electronic solid. In realistic samples, a domain structure forms in the solid and each domain randomly orients in the absence of the in-plane field. At higher temperature, the electron transport is governed by thermal activation form of $\sigma_{xx}(T)\propto e^{-\Delta_0/k_BT}$. The impurities will localize the electron states along the edges of the crystal domains. At sufficient low temperature, another transport mechanism called Mott's variable range hopping mechanism, similar to that in a disorder insulator takes effect. We show that as the temperature decreases, a crossover from the fixed range hopping of the transport to the variable range hopping of transport in the 2D electron system may be experimentally observed.Comment: 4 pages,1 figure

Synthesis, Structure and Magnetic Properties of New Layered Iron-Oxychalcogenide Na2Fe2OSe2

A new layered iron-oxychalcogenide Na2Fe2OSe2 has been synthesized and structurally characterized by powder X-ray diffraction. The structure is formed by alternate stacking of the newly discovered [Fe2OSe2] blocks and double layers of Na. Conductivity study shows that Na2Fe2OSe2 is a semiconductor with activation energy of 0.26 eV. Magnetic susceptibility and heat capacity measurements reveal an antiferromagnetic phase transition occurs at TN=73 K. A broad maximum of magnetic susceptibility and a slow decay of the specific heat above TN, arises as a result of two-dimensional short-range spin correlation.Comment: 4 pages, 4 figure

Two successive field-induced spin-flop transitions in single-crystalline CaCo2_{2}As2_{2}

CaCo$_{2}$As$_{2}$, a ThCr$_{2}$Si$_{2}$-structure compound, undergoes an antiferromagnetic transition at \emph{T$_{N}$}=76K with the magnetic moments being aligned parallel to the \emph{c} axis. Electronic transport measurement reveals that the coupling between conducting carriers and magnetic order in CaCo$_{2}$As$_{2}$ is much weaker comparing to the parent compounds of iron pnictide. Applying magnetic field along \emph{c} axis induces two successive spin-flop transitions in its magnetic state. The magnetization saturation behaviors with \emph{\textbf{H}$\parallel$c} and \emph{\textbf{H}$\parallel$ab} at 10K indicate that the antiferromagnetic coupling along \emph{c} direction is very weak. The interlayer antiferromagntic coupling constant \emph{J$_{c}$} is estimated to be about 2 meV.Comment: Accepted for publication in Phys. Rev. B. 5 pages, 6 figure