TY - JOUR

T1 - Intrinsic and magnetic-field-induced linear polarization of excitons in ultrathin indirect-gap type-II GaAs/AlAs quantum wells

AU - Shamirzaev, T. S.

AU - Rautert, J.

AU - Yakovlev, D. R.

AU - Glazov, M. M.

AU - Bayer, M.

PY - 2019/4/5

Y1 - 2019/4/5

N2 - The exciton dynamics in transverse magnetic field is investigated both experimentally and theoretically in two-monolayer-thick GaAs/AlAs quantum wells with an indirect band gap and a type-II band alignment. The observed linear polarization of the quantum well photoluminescence has two contributions, one of which arises from the crystalline structure of the quantum well. It does not depend on temperature and demonstrates a strong spectral dependence across the emission band. The other one is induced by a transverse magnetic field. It strongly decreases with increasing temperature, has no spectral dependence, and demonstrates an unexpectedly long-time dynamics. The experimental findings can be explained in the framework of the developed theoretical model which accounts for the quantum well anisotropy, the Zeeman effect of electrons and holes in the transverse magnetic field, and the redistribution of excitons over the spin sublevels. It provides quantitative agreement with the experiment and allows us to evaluate, for the studied structure, the heavy-hole in-plane g-factor tensor, which turns out to be extremely anisotropic with principal values of opposite signs and the same magnitude of 0.25.

AB - The exciton dynamics in transverse magnetic field is investigated both experimentally and theoretically in two-monolayer-thick GaAs/AlAs quantum wells with an indirect band gap and a type-II band alignment. The observed linear polarization of the quantum well photoluminescence has two contributions, one of which arises from the crystalline structure of the quantum well. It does not depend on temperature and demonstrates a strong spectral dependence across the emission band. The other one is induced by a transverse magnetic field. It strongly decreases with increasing temperature, has no spectral dependence, and demonstrates an unexpectedly long-time dynamics. The experimental findings can be explained in the framework of the developed theoretical model which accounts for the quantum well anisotropy, the Zeeman effect of electrons and holes in the transverse magnetic field, and the redistribution of excitons over the spin sublevels. It provides quantitative agreement with the experiment and allows us to evaluate, for the studied structure, the heavy-hole in-plane g-factor tensor, which turns out to be extremely anisotropic with principal values of opposite signs and the same magnitude of 0.25.

KW - SPIN RELAXATION

KW - HEAVY

U2 - 10.1103/PhysRevB.99.155301

DO - 10.1103/PhysRevB.99.155301

M3 - статья

VL - 99

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 15

M1 - 155301

ER -