Rashba spin-splitting of single electrons and Cooper pairs

Electric weak links, the term used for those parts of an electrical circuit that provide most of the resistance against the flow of an electrical current, are important elements of many nanodevices. Quantum dots, nanowires and nano-constrictions that bridge two bulk conductors (or superconductors) are examples of such weak links. Here we consider nanostructures where the electronic spin-orbit interaction is strong in the weak link but is un-important in the bulk conductors, and explore theoretically the role of the spin-orbit active weak link (which we call a “Rashba spin splitter”) as a source of new spin-based functionality in both normal and superconducting devices. Some recently predicted phenomena, including mechanically-controlled spin- and charge currents as well as the effect of spin polarization of superconducting Cooper pairs, are reviewed

Photo-spintronics of spin-orbit active electric weak links

We show that a carbon nanotube can serve as a functional electric weak link performing photo-spintronic transduction. A spin current, facilitated by strong spin-orbit interactions in the nanotube and not accompanied by a charge current, is induced in a device containing the nanotube weak link by circularly polarized microwaves. Nanomechanical tuning of the photo-spintronic transduction can be achieved due to the sensitivity of the spinorbit interaction to geometrical deformations of the weak link

Rashba proximity states in superconducting tunnel junctions

We consider a new kind of superconducting proximity effect created by the tunneling of “spin split” Cooper pairs between two conventional superconductors connected by a normal conductor containing a quantum dot. The difference compared to the usual superconducting proximity effect is that the spin states of the tunneling Cooper pairs are split into singlet and triplet components by the electron spin-orbit coupling, which is assumed to be active in the normal conductor only. We demonstrate that the supercurrent carried by the spin-split Cooper pairs can be manipulated both mechanically and electrically for strengths of the spin-orbit coupling that can realistically be achieved by electrostatic gates

Mechanically driven spin-orbit-active weak links

We show that new functionality of spin-orbit-active electronic weak links can be achieved by their time- dependent mechanical deformation. As an illustration we use a simple model to calculate the electronic spin cur- rent generated by rotating a bent spin-orbit-active nanowire coupled to bulk metallic leads. © M. Jonson, R.I. Shekhter, O. Entin-Wohlman, A. Aharony, H.C. Park, and D. Radić, 201811sci

Mechanically driven spin-orbit-active weak links

We show that new functionality of spin-orbit-active electronic weak links can be achieved by their timedependent mechanical deformation. As an illustration we use a simple model to calculate the electronic spin current generated by rotating a bent spin-orbit-active nanowire coupled to bulk metallic leads.Обговорюються нові функціональні можливості, що реалізовуються у тунельних структурах завдяки залежній від часу сильній спін-орбітальній взаємодії електронів. Як приклад запропоновано просту модель, в якій передбачено генерацію спінового струму, що виникає при обертанні зігнутого дроту, який з’єднує два масивні метали, із локалізованою на ній сильною спін-орбітальною взаємодією електронів.Обсуждаются новые функциональные возможности, реализующиеся в туннельных структурах благодаря зависящему от времени сильному спин-орбитальному взаимодействию электронов. В качестве примера предложена простая модель, в которой предсказана генерация спинового тока, возникающая при вращении изогнутой проволоки, соединяющей два массивных металла, с локализованным на ней сильным спинорбитальным взаимодействием электронов