On the pure state outcomes of Einstein-Podolsky-Rosen steering

In the Einstein--Podolsky--Rosen experiment, when Alice makes a measurement on her part of a bipartite system, Bob's part is collapsed to, or steered to, a specific ensemble. Moreover, by reading her measurement outcome, Alice can specify which state in the ensemble Bob's system is steered to and with which probability. The possible states that Alice can steer Bob's system to are called steered states. In this work, we study the subset of steered states which are pure after normalisation. We illustrate that these pure steered states, if they exist, often carry interesting information about the shared bipartite state. This information content becomes particularly clear when we study the purification of the shared state. Some applications are discussed. These include a generalisation of the fundamental lemma in the so-called `all-versus-nothing proof of steerability' for systems of arbitrary dimension.Comment: 7 pages, 0 figures; corrected typos and terminolog

Entanglement dynamics of two mesoscopic objects with gravitational interaction

We analyse the entanglement dynamics of the two particles interacting through gravity in the recently proposed experiments aiming at testing quantum signatures for gravity [Phy. Rev. Lett 119, 240401 & 240402 (2017)]. We consider the open dynamics of the system under decoherence due to the environmental interaction. We show that as long as the coupling between the particles is strong, the system does indeed develop entanglement, confirming the qualitative analysis in the original proposals. We show that the entanglement is also robust against stochastic fluctuations in setting up the system. The optimal interaction duration for the experiment is computed. A condition under which one can prove the entanglement in a device-independent manner is also derived.Comment: 5 pages, 3 figures; comments are welcome

Criticality-Enhanced Precision in Phase Thermometry

Temperature estimation of interacting quantum many-body systems is both a challenging task and topic of interest in quantum metrology, given that critical behavior at phase transitions can boost the metrological sensitivity. Here we study non-invasive quantum thermometry of a finite, two-dimensional Ising spin lattice based on measuring the non-Markovian dephasing dynamics of a spin probe coupled to the lattice. We demonstrate a strong critical enhancement of the achievable precision in terms of the quantum Fisher information, which depends on the coupling range and the interrogation time. Our numerical simulations are compared to instructive analytic results for the critical scaling of the sensitivity in the Curie-Weiss model of a fully connected lattice and to the mean-field description in the thermodynamic limit, both of which fail to describe the critical spin fluctuations on the lattice the spin probe is sensitive to. Phase metrology could thus help to investigate the critical behaviour of finite many-body systems beyond the validity of mean-field models.Comment: 11 pages, 8 figure

Static and vibration analysis of isotropic and functionally graded sandwich plates using an edge-based MITC3 finite elements

Static and vibration analysis of isotropic and functionally graded sandwich plates using a higher-order shear deformation theory is presented in this paper. Lagrangian functional is used to derive the equations of motion. The mixed interpolation of tensorial components (MITC) approach and edge-based-strain technique is used to solve problems. A MITC3 three-node triangle element with 7 degree-of-freedoms per nodes that only requires the C0-type continuity is developed. Numerical results for isotropic and functionally graded sandwich plates with different boundary conditions are proposed to validate the developed theory and to investigate effects of material distribution, side-to-thickness ratio, thickness ratio of layers and boundary conditions on the deflection, stresses and natural frequencies of the plates

Epidemiologic Attributes and Virulence Profile of Salmonella Tennessee isolates from Infections associated with Peanut Butter National Outbreak

The multi-state outbreak of Salmonella serotype Tennessee infections associated with peanut butter during 2006-2007 was the first outbreak in the United States associated with this food vehicle.  We investigated whether the outbreak-related strains had any distinct virulence attributes. We have analyzed 96 representative isolates from human and non-human sources from multiple states for attachment and invasion of caco-2 cell. In logistic regression analysis, we found that Salmonella Tennessee strains associated with the peanut butter outbreak were more likely to be highly invasive than strains from non-outbreak sources, OR 4.03 (95% CI 1.42, 11.41). Results from this study suggest that peanut butter could have provided an impetus for the expression of certain sets of virulence genes leading to the observed high level of invasiveness of the Salmonella Tennessee contaminants.  The occurrence of this outbreak underscores the importance of hygienic practices in peanut butter manufacturing plants for the prevention of such mass contamination. Keywords: Salmonella Tennessee; peanut butter; newly emerging food vehicles for Salmonella; risk factors for Salmonella Tennesse

Magic configurations in Moir\'e Superlattice of Bilayer Photonic crystal: Almost-Perfect Flatbands and Unconventional Localization

We investigate the physics of photonic band structures of the moir\'e patterns that emerged when overlapping two uni-dimensional (1D) photonic crystal slabs with mismatched periods. The band structure of our system is a result of the interplay between intra-layer and inter-layer coupling mechanisms, which can be fine-tuned via the distance separating the two layers. We derive an effective Hamiltonian that captures the essential physics of the system and reproduces all numerical simulations of electromagnetic solutions with high accuracy. Most interestingly, \textit{magic distances} corresponding to the emergence of photonic flatbands within the whole Brillouin zone of the moir\'e superlattice are observed. We demonstrate that these flatband modes are tightly localized within a moir\'e period. Moreover, we suggest a single-band tight-binding model that describes the moir\'e minibands, of which the tunnelling rate can be continuously tuned via the inter-layer strength. Our results show that the band structure of bilayer photonic moir\'e can be engineered in the same fashion as the electronic/excitonic counterparts. It would pave the way to study many-body physics at photonic moir\'e flatbands and novel optoelectronic devices.Comment: 6 pages + Supplement. Comments are welcome