Ballistic spin filtering across the ferromagnetic-semiconductor interface

Abstract

The ballistic spin-filter effect from a ferromagnetic metal into a semiconductor has theoretically been studied with an intention of detecting the spin polarizability of density of states in FM layer at a higher energy level. The physical model for the ballistic spin filtering across the interface between ferromagnetic metals and semiconductor superlattice is developed by exciting the spin polarized electrons into n-type AlAs/GaAs superlattice layer at a much higher energy level and then ballistically tunneling through the barrier into the ferromagnetic film. Since both the helicity-modulated and static photocurrent responses are experimentally measurable quantities, the physical quantity of interest, the relative asymmetry of spin-polarized tunneling conductance, could be extracted experimentally in a more straightforward way, as compared with previous models. The present physical model serves guidance for studying spin detection with advanced performance in the future.

Детекторы циркулярно-поляризованного излучения на основе полупроводниковых гетероструктур с барьером Шоттки CoPt

“…Одним из основных направлений по созданию детекторов циркулярно-поляризованного излучения является использование систем " ферромагнитный металл/полупроводниковая структура". Анализ работ, описывающих конструкцию фотодетекторов, показывает, что большинство из них сформировано на основе полупроводниковых структур A 3 B 5 , а в качестве ферромагнитного слоя в основном используются металлические материалы, для которых установлена возможность эффективной спиновой инжекции (Fe, NiFe, CoFe, CoFeB) [2][3][4].…”

Opto-spintronics in InP using ferromagnetic tunnel spin filters

“…In order to detect electrically the optically excited spins in a SC, tunneling the spins into a ferromagnetic (FM) spin filter contact has been proven advantageous [18,19]. In the case of GaAs as the SC, tunnel spin injection of spin-pumped electrons into various FM metals was demonstrated with so-called spin diode structures [20][21][22], and recently theoretically described by Li [23]. The working principle of the 'spin diodes' was based on the irradiation of photons though a homogenous closed GaAs/Schottky/FM layer structure [8,22,[24][25][26].…”

Electrical detection of spin hyperpolarization in InP

“…[9][10][11] Tunnel spin injection of spin-pumped electrons into various ferromagnets (FM) was shown to be efficient in the case of GaAs: Isakovic et al, 12 Nakajima et al, 13 and Hirohata et al 14 used the so-called spin diode structures, which were theoretically described by Li. 15 The spin excitation of the "spin diodes" was based on photon irradiation through a GaAs/Schottky/FM stack 14,[16][17][18][19] of macroscopic extent. In this scheme, the electrical spin detection is complicated by the additional interactions of photons with the FM.…”