TY - JOUR

T1 - Large anisotropic spin relaxation time of exciton bound to donor states in triple quantum wells

AU - Ullah, S.

AU - Gusev, G. M.

AU - Bakarov, A. K.

AU - Hernandez, F. G.G.

PY - 2017/5/28

Y1 - 2017/5/28

N2 - We have studied the spin dynamics of a dense two-dimensional electron gas confined in a GaAs/AlGaAs triple quantum well by using time-resolved Kerr rotation and resonant spin amplification. Strong anisotropy of the spin relaxation time up to a factor of 10 was found between the electron spins oriented in-plane and out-of-plane when the excitation energy is tuned to an exciton bound to neutral donor transition. We model this anisotropy using an internal magnetic field and the inhomogeneity of the electron g-factor. The data analysis allows us to determine the direction and magnitude of this internal field in the range of a few mT for our studied structure, which decreases with the sample temperature and optical power. The dependence of the anisotropic spin relaxation was directly measured as a function of several experimental parameters: excitation wavelength, sample temperature, pump-probe time delay, and pump power.

AB - We have studied the spin dynamics of a dense two-dimensional electron gas confined in a GaAs/AlGaAs triple quantum well by using time-resolved Kerr rotation and resonant spin amplification. Strong anisotropy of the spin relaxation time up to a factor of 10 was found between the electron spins oriented in-plane and out-of-plane when the excitation energy is tuned to an exciton bound to neutral donor transition. We model this anisotropy using an internal magnetic field and the inhomogeneity of the electron g-factor. The data analysis allows us to determine the direction and magnitude of this internal field in the range of a few mT for our studied structure, which decreases with the sample temperature and optical power. The dependence of the anisotropic spin relaxation was directly measured as a function of several experimental parameters: excitation wavelength, sample temperature, pump-probe time delay, and pump power.

KW - COHERENCE

KW - ELECTRONS

KW - SEMICONDUCTORS

KW - AMPLIFICATION

KW - SYSTEM

KW - GAAS

UR - http://www.scopus.com/inward/record.url?scp=85020006583&partnerID=8YFLogxK

U2 - 10.1063/1.4984118

DO - 10.1063/1.4984118

M3 - Article

AN - SCOPUS:85020006583

VL - 121

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 20

M1 - 205703

ER -