High Temperature Gate Control of Quantum Well Spin Memory

Abstract

Time-resolved optical measurements in (110)-oriented GaAs/AlGaAs quantum wells show a tenfold increase of the spin-relaxation rate as a function of applied electric field from 20 to 80 kV cm(-1) at 170 K and indicate a similar variation at 300 K, in agreement with calculations based on the Rashba effect. Spin relaxation is almost field independent below 20 kV cm(-1) reflecting quantum well interface asymmetry. The results indicate the achievability of a voltage-gateable spin-memory time longer than 3 ns simultaneously with a high electron mobility.

Spin relaxation in quantum dots with random spin-orbit coupling

“…It is important to mention that by applying an external bias across the quantum well, it is possible to manipulate the magnitude of α in InGaAs/InAlAs-based 17 and GaAs/AlAs-based [18][19][20] systems and even change its sign by doping 21 . In the asymmetric Si/Si 1−x Ge x quantum wells investigated in Refs.…”

Spin Relaxation by Transient Monopolar and Bipolar Optical Orientation

“…DOI: 10.1103/PhysRevLett.96.096603 PACS numbers: 72.25.Rb, 72.25.Fe, 78.47.+p Spin polarizations have become a focus of interest in semiconductor physics in recent years, not least for their potential application in ''spintronic'' devices [1]. It has been shown that spin polarized electrons (or holes) can be injected from magnetic semiconductor materials into semiconductors [2,3], that they can be coherently transported through a device [4], and that they can be controlled (or modulated) with an external electric field [5]. It remains challenging to improve these breakthroughs to the extent that they can be combined in a practical device [1].…”

“…, m e is the electron effective mass ratio and is the spin orbit split-off energy [19] We performed circularly polarized pump-probe experiments using transient induced Faraday rotation, similar to those described elsewhere [4][5][6], with the difference being that the pump and the probe originated from two different lasers. The pump beam was the free electron laser, FELIX, which produces (sub-) picosecond pulses and is continuously tunable from 4-250 m. The probe beam was taken from a solid state laser system (pumped by an amplified mode-locked Ti:sapphire laser) producing subpicosecond midinfrared pulses from 3:3-18 m. The lasers were synchronized with an rf phase locked loop.…”

Strain-induced spin relaxation anisotropy in symmetric (001)-oriented GaAs quantum wells

“…6,7 The different contributions in general each have a different dependence on p and can be varied independently of one another by the design of the heterostructure [8][9][10] or by the application of external perturbations. [11][12][13][14] Consequently, the interplay of the contributions that make up the resultant effective magnetic field, (p) = BIA + SIA + STR , offers many possibilities for external control of the spin dynamics, including complete cancellation of one or more Cartesian components of (p). 11,12,15 Spin rotation of a polarized electron population has been directly observed under a uniform imposed drift, 7,[16][17][18] under movement by a surface acoustic wave, 19 and also for electrons at the Fermi momentum in a degenerate two-dimensional (2D) electron gas.…”