Andreev-like reflections with cold atoms

We propose a setup in which Andreev-like reflections predicted for 1D transport systems could be observed time dependently using cold atoms in a 1D optical lattice. Using time-dependent density matrix renormalization group methods we analyze the wave packet dynamics as a density excitation propagates across a boundary in the interaction strength. These phenomena exhibit good correspondence with predictions from Luttinger liquid models and could be observed in current experiments in the context of the Bose-Hubbard model

Stochastic Gross-Pitaevsky Equation for BEC via Coarse-Grained Effective Action

We sketch the major steps in a functional integral derivation of a new set of Stochastic Gross-Pitaevsky equations (GPE) for a Bose-Einstein condensate (BEC) confined to a trap at zero temperature with the averaged effects of non-condensate modes incorporated as stochastic sources. The closed-time-path (CTP) coarse-grained effective action (CGEA) or the equivalent influence functional method is particularly suitable because it can account for the full back-reaction of the noncondensate modes on the condensate dynamics self-consistently. The Langevin equations derived here containing nonlocal dissipation together with colored and multiplicative noises are useful for a stochastic (as distinguished from say, a kinetic) description of the nonequilibrium dynamics of a BEC. This short paper contains original research results not yet published anywhere.Comment: 6 page

High energy neutrino in a nuclear environment: mirror asymmetry of the shadowing effect

The parity non-conservation effect in diffractive charged current DIS is quantified in terms of color dipole sizes of left-handed and right-handed electroweak bosons. We identify the origin and estimate the strength of the left-right asymmetry effect and present comparison with experimental data on the parity-odd structure function $\Delta xF_3 =xF_3^{\nu N}-xF_3^{\bar\nu N}$. We study the shadowing effect in absorption of left-handed and right-handed $W$-bosons by atomic nuclei. The target nucleus is found to be quite transparent for the charmed-strange Fock component of the light-cone $W^+$ in the helicity state $\lambda=+1$ and rather opaque for the $c\bar s$ dipole with $\lambda=-1$.Comment: 11 pages, 2 figures, Talk presented at XXXIII International Conference on High Energy Physics 26.07.06-02.08.06 Moscow, version to be publishe

Unitary nn-designs via random quenches in atomic Hubbard and Spin models: Application to the measurement of R\'enyi entropies

We present a general framework for the generation of random unitaries based on random quenches in atomic Hubbard and spin models, forming approximate unitary $n$-designs, and their application to the measurement of R\'enyi entropies. We generalize our protocol presented in [Elben2017: arXiv:1709.05060, to appear in Phys. Rev. Lett.] to a broad class of atomic and spin lattice models. We further present an in-depth numerical and analytical study of experimental imperfections, including the effect of decoherence and statistical errors, and discuss connections of our approach with many-body quantum chaos.Comment: This is a new and extended version of the Supplementary material presented in arXiv:1709.05060v1, rewritten as a companion paper. Version accepted to Phys. Rev. A. Minus sign corrected in Eq (5