arXiv subjects

A. V. Poshakinskiy

Publications and source records attributed to A. V. Poshakinskiy.

40 records · Page 3Linked to original sources

arXiv2013

Effect of Dresselhaus spin-orbit coupling on spin dephasing in asymmetric and macroscopically symmetric (110)-grown quantum wells

We develop the microscopic theory of electron spin dephasing in (110)-grown quantum wells where the electron scattering time is comparable to or exceeds the period of spin precession in the effective magnetic field caused by spin-orbit coupling. Structures with homogeneous and fluctuating Rashba field, which triggers the dephasing of electron spins aligned along the growth direction, are analyzed. We show that the Dresselhaus field, which is always present in zinc-blende-type quantum wells, suppresses the spin dephasing enabling very long spin lifetime of conduction electrons. The dependence of the spin lifetime on the electron mobility is found to be nonmonotonic reaching the minimum in structures where the scattering time is comparable to the period of spin precession in the effective magnetic field.

cond-mat.mes-hall↗

arXiv2012

Reflection of short polarized optical pulses from periodic and aperiodic multiple quantum well structures

We study the reflection of polarized optical pulses from resonant photonic structures formed by periodic, Fibonacci, and gradient sequences of quantum wells. The form and polarization of the reflected pulse are shown to be determined by the structure design and optical length. In structures with periodic quantum well arrangement, the response to ultrashort pulse is an optical signal with a sharp rise followed by an exponential decay or Bessel beats depending on the structure length. The duration of reflected pulses non-monotonically depends on the number of quantum wells reaching the minimum for a certain structure length which corresponds to the transition from superradiant to photonic-crystalline regime. We also study the conversion of pulse polarization in the longitudinal external magnetic field which splits the exciton resonance. Comparing periodic, Fibonacci, and gradient structures we show that the latter are more efficient for the conversion from linear to circular polarization.

cond-mat.mes-hall↗

arXiv2011

Electron spin dephasing in two-dimensional systems with anisotropic scattering

We develop a microscopic theory of spin relaxation of a two-dimensional electron gas in quantum wells with anisotropic electron scattering. Both precessional and collision-dominated regimes of spin dynamics are studied. It is shown that, in quantum wells with noncentrosymmetric scatterers, the in-plane and out-of-plane spin components are coupled: spin dephasing of carriers initially polarized along the quantum well normal leads to the emergence of an in-plane spin component even in the case of isotropic spin-orbit splitting. In the collision-dominated regime, the spin-relaxation-rate tensor is expressed in terms of the electric conductivity tensor. We also study the effect of an in-plane and out-of-plane external magnetic field on spin dephasing and show that the field dependence of electron spin can be very intricate.

cond-mat.mes-hall↗

arXiv2011

Spin-orbit Hanle effect in high-mobility quantum wells

We study the depolarization of optically oriented electrons in quantum wells subjected to an in-plane magnetic field and show that the Hanle curve drastically depends on the carrier mobility. In low-mobility structures, the Hanle curve is described by a Lorentzian with the width determined by the effective g-factor and the spin lifetime. In contrast, the magnetic field dependence of spin polarization in high-mobility quantum wells is nonmonotonic: The spin polarization rises with the magnetic field induction at small fields, reaches maximum and then decreases. We show that the position of the Hanle curve maximum can be used to directly measure the spin-orbit Rashba/Dresselhaus magnetic field.

cond-mat.mes-hall↗