Relaxation mechanisms of the persistent spin helix

Abstract

We study the lifetime of the persistent spin helix in semiconductor quantum wells with equal Rashba- and linear Dresselhaus spin-orbit interactions. In order to address the temperature dependence of the relevant spin relaxation mechanisms we derive and solve semiclassical spin diffusion equations taking into account spin-dependent impurity scattering, cubic Dresselhaus spin-orbit interactions and the effect of electron-electron interactions. For the experimentally relevant regime we find that the lifetime of the persistent spin helix is mainly determined by the interplay of cubic Dresselhaus spin-orbit interaction and electron-electron interactions. We propose that even longer lifetimes can be achieved by generating a spatially damped spin profile instead of the persistent spin helix state.Comment: 12 pages, 2 figure

Dynamics of a localized spin excitation close to the spin-helix regime

“…Using a density-matrix response function with standard perturbation theory [14][15][16] , or starting from a semiclassical spin kinetic equation 17 , the following equation is obtained:…”

Gate-controlled persistent spin helix state in (In,Ga)As quantum wells

“…While the weak kcubic SOI in this experiment barely affects the PSH formation, the important question arises whether a PSH-type state will generally survive in materials with strong SOI where finite kcubic terms gain importance, in particular for heterostructures at higher charge carrier densities. Also, compared to the linear case, much less is known theoretically [14][15][16][17] about the robustness of the PSH in this general case.In this Rapid Communication we demonstrate in two complementary independent, transport and optical, experiments the formation of a PSH state in a material with strong SOI, InGaAs quantum wells. On the one hand, we consider quantum corrections to the magnetoconductance to detect the PSH: While SOI generally leads to spin randomization and thereby to weak antilocalization (WAL), 18 systems with linear SOI obeying α = ±β, where spins are not rotated along closed back-scattered trajectories, should exhibit weak localization (WL).…”

“…While the weak kcubic SOI in this experiment barely affects the PSH formation, the important question arises whether a PSH-type state will generally survive in materials with strong SOI where finite kcubic terms gain importance, in particular for heterostructures at higher charge carrier densities. Also, compared to the linear case, much less is known theoretically [14][15][16][17] about the robustness of the PSH in this general case.…”

Влияние Электрического Поля На Соотношение Параметров Рашба И Дрессельхауза В Гетероструктурах А-=sup=-Iii-=/Sup=-B-=sup=-v-=/Sup=-

“…В частности, в наиболее распространен-ном случае А III B V квантовых ям (КЯ) с направлением роста [001] при определенных соотношениях между параметрами СОВ возможна реализация спиновой SU(2) симметрии [5]. В таких КЯ заметно снижается скорость спиновой релаксации электронов проводимости [6], что расширяет возможности проектирования спиновых при-боров на их основе.…”