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Related papers: Linear response study of collisionless spin drag

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We study theoretically the differential conductance at a junction between a time reversal symmetry broken spin orbit coupled system with a tunable band gap and a superconductor. We look for spin-dependent Andreev reflection (i.e, sub-gap…

Mesoscale and Nanoscale Physics · Physics 2018-12-14 Dibya Kanti Mukherjee , Joanna Hutchinson , Arijit Kundu

We study the flow of a weakly-interacting Bose-Einstein condensate around an obstacle by numerical solution of the Gross-Pitaevskii equation. We observe vortex emission and the formation of bow waves leading to pressure drag. We compare the…

Statistical Mechanics · Physics 2009-10-31 T. Winiecki , J. F. McCann , C. S. Adams

We observe spin rotations caused by atomic collisions in a non-equilibrium Bose-condensed gas of $^{87}$Rb. Reflection from a pseudomagnetic barrier creates counterflow in which forward- and backward-propagating matter waves have partly…

Quantum Gases · Physics 2024-04-25 David C. Spierings , Joseph H. Thywissen , Aephraim M. Steinberg

We study the bosonic analog of Andreev reflection at a normal-superfluid interface where the superfluid is a boson condensate. We model the normal region as a zone where nonlinear effects can be neglected. Against the background of a…

Other Condensed Matter · Physics 2009-07-22 I. Zapata , F. Sols

Andreev reflection is a fundamental transport process occurring at the junction between a normal metal and a superconductor (a N-S junction), when an incident electron from the normal side can only be transmitted in the superconductor as a…

We investigate a model of a two-component Bose-Einstein condensate residing on an optical lattice. Within a Bogolioubov-approach at the mean-field level, we derive exact analytical expressions for the excitation spectrum of the…

Quantum Gases · Physics 2009-06-08 Jacob Linder , Asle Sudbø

The Andreev Reflection is the key mechanism for the superconducting proximity effect. It provides phase correlations in a system of non-interacting electrons at mesoscopic scales, i.e. over distances much larger than the microscopic lengths…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 B. Pannetier , H. Courtois

In this work, we generalize the two-fluid theory to a superfluid system with anisotropic effective masses along different principal axis directions. As a specific example, such a theory can be applied to spin-orbit coupled Bose-Einstein…

Quantum Gases · Physics 2019-04-26 Yi-Cai Zhang , Chao-Fei Liu , Bao Xu , Gang Chen , W. M. Liu

We study two-species Bose-Einstein condensates in quasi two-dimensional optical lattices of varying geometry and potential depth. Based on the numerically exact Bloch and Wannier functions obtained using the plane-wave expansion method, we…

Quantum Gases · Physics 2012-09-25 Patrick P. Hofer , C. Bruder , Vladimir M. Stojanovic

The artificial magnetic fields engineered for ultra cold gases depend on the internal structure of the neutral atoms. Therefore the components of a mixture composed of two atomic gases can exhibit a different response to an artificial…

Quantum Gases · Physics 2019-07-02 S. Seyyare Aksu , A. Levent Subaşı , Nader Ghazanfari

We theoretically analyze non-local effects in electron transport across three-terminal ballistic normal-superconducting-normal (NSN) structures with spin-active interfaces. Subgap electrons entering S-electrode from one N-metal may form…

Superconductivity · Physics 2007-12-11 Mikhail S. Kalenkov , Andrei D. Zaikin

We present an analytical result for the supercurrent across a superconductor/quantum-dot/superconductor junction. By converting the current integration into a special contour integral, we can express the current as a sum of the residues of…

Mesoscale and Nanoscale Physics · Physics 2018-01-17 Wei Li , Yu Zhu , Tsung-han Lin

We apply a recently developed effective string theory for vortex lines to the case of two-dimensional trapped superfluids. We do not assume a perturbative microscopic description for the superfluid, but only a gradient expansion for the…

High Energy Physics - Theory · Physics 2017-09-20 Angelo Esposito , Rafael Krichevsky , Alberto Nicolis

We theoretically study the superconducting proximity effect in silicene, which features massive Dirac fermions with a tunable mass (band gap), and compute the conductance across a normal/superconductor (N/S) silicene junction, the non-local…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Jacob Linder , Takehito Yokoyama

We investigate the drag force on a moving impurity in a spin-orbit coupled Bose-Einstein condensate. We prove rigorously that the superfluid critical velocity is zero when the impurity moves in all but one directions, in contrast to the…

Quantum Gases · Physics 2015-06-19 Pei-Song He , Yao-Hui Zhu , Wu-Ming Liu

We study the role of electron-electron interactions for spin polarized transport using the Boltzmann equation and derive a set of coupled transport equations. For spin polarized transport the electron-electron interactions are important,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Karsten Flensberg , Thomas Stibius Jensen , Niels Asger Mortensen

Spin effects in a normal two-dimensional (2D) electron gas in lateral contact with a 2D region with spin-orbit interaction are studied. The peculiarity of this system is the presence of spin-dependent scattering of electrons from the…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Aleksei A. Sukhanov , Vladimir A. Sablikov , Yurii Ya. Tkach

We study the drag force on objects moving in a Fermi superfluid at velocities on the order of the Landau velocity $v_L$. The expectation has been that $v_L$ is the critical velocity beyond which the drag force starts to increase towards its…

Superconductivity · Physics 2018-10-24 J. A. Kuorelahti , S. M. Laine , E. V. Thuneberg

We study Andreev reflection in normal metal-superconductor junctions by using an extended Blonder-Tinkham-Klapwijk model combined with transport calculations based on density functional theory. Starting from a parameter-free description of…

Mesoscale and Nanoscale Physics · Physics 2014-10-28 Awadhesh Narayan , Ivan Rungger , Stefano Sanvito

We study superfluid drag in the two-component Bose-Hubbard model with infinitely strong repulsive interactions. In this system, all transport is mediated by the motion of empty sites, or ``holes", and it is hard to move one component…

Quantum Gases · Physics 2025-04-03 Thomas G. Kiely , Chao Zhang , Erich J. Mueller