2 7 Ja n 20 05 Photo - induced pure spin currents in quantum wells
نویسندگان
چکیده
As is well known the absorption of circularly polarized light in semiconductors results in optical orientation of electron spins and helicity-dependent electric photocurrent, and the absorption of linearly polarized light is accompanied by optical alignment of electron momenta. Here we show that the absorption of unpolarized light in a quantum well (QW) leads to generation of a pure spin current, although both the average electron spin and electric current are vanishing.
منابع مشابه
ar X iv : c on d - m at / 0 30 13 89 v 1 2 1 Ja n 20 03 Spin - photocurrent in p - SiGe quantum wells under terahertz laser irradiation
A detailed study of the circular photogalvanic effect (CPGE) in SiGe structures is presented. It is shown that the CPGE becomes possible due to the built-in asymmetry of quantum wells (QWs) in compositionally stepped samples and in asymmetrically doped structures. The photocurrent arises due to optical spin orientation of free carriers in QWs with spin splitting in k-space. It is shown that the...
متن کاملar X iv : c on d - m at / 0 30 13 88 v 1 2 1 Ja n 20 03 Optical Spin Orientation under Inter - and Intra - Subband Transitions in QWs
It is shown that absorption of circularly polarized infrared radiation achieved by inter-subband and intra-subband (Drude-like) transitions results in a monopolar spin orientation of free carriers. The monopolar spin polarization in zinc-blende-based quantum wells (QWs) is demonstrated by the observation of the spin-galvanic and circular photogalvanic effects. It is shown that monopolar spin or...
متن کاملQuantum interference control of ballistic pure spin currents in semiconductors.
We demonstrate all-optical quantum interference injection and control of a ballistic pure spin current (without an accompanying charge current) in GaAs/AlGaAs quantum wells, consisting of spin-up electrons traveling in one direction and spin-down electrons traveling in the opposite direction. This current is generated through quantum interference of one- and two-photon absorption of approximate...
متن کاملar X iv : h ep - t h / 05 01 21 8 v 1 2 7 Ja n 20 05 Radial evolution in anti - de Sitter spacetime
We derive properties of the radial evolution of scalar fields in anti-de Sitter spacetime from quantum mechanics, through a factorisation of the path integral. We describe why we anticipate application of these results to the AdS/CFT correspondence.
متن کاملar X iv : h ep - p h / 05 01 25 4 v 1 2 7 Ja n 20 05 UT - 05 - 01 Strongly Coupled Gauge Mediation
A model of gauge mediation with m 3/2 ≃ O(1) eV is considered to motivate 100 TeV colliders. Massive mediators with standard-model and supersymmetry-breaking gauge quantum numbers let low-scale dynamics induce sizable soft masses of the standard-model superpartners. We circumvent potential phenomenological difficulties that such low-scale models tend to cause.
متن کامل