Article

Magnetogyrotropic photogalvanic effect and spin dephasing in (110)-grown GaAs/Al_ {x} Ga_ {1− x} As quantum well structures

Physical review. B, Condensed matter (Impact Factor: 3.66). 06/2009; 79(24). DOI: 10.1103/PhysRevB.79.245329
Source: arXiv

ABSTRACT We report the magnetogyrotropic photogalvanic effect (MPGE) in n-doped (110)-grown GaAs/AlGaAs quantum-well (QW) structures caused by free-carrier absorption of terahertz radiation in the presence of a magnetic field. The photocurrent behavior upon variation in the radiation-polarization state, magnetic field orientation, and temperature is studied. The developed theory of MPGE describes well all experimental results. It is demonstrated that the structure inversion asymmetry can be controllably tuned to zero by variation in the delta-doping layer positions. For the in-plane magnetic field the photocurrent is only observed in asymmetric structures but vanishes in symmetrically doped QWs. Applying time-resolved Kerr rotation and polarized luminescence we investigate the spin relaxation in QWs for various excitation levels. Our data confirm that in symmetrically doped QWs the spin-relaxation time is maximal; therefore, these structures set the upper limit of spin dephasing in GaAs/AlGaAs QWs.
.

0 Bookmarks
 · 
71 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We experimentally studied the magneto-photocurrents generated by direct interband transition in InAs/GaSb type II superlattice. By varying the magnetic field direction, we observed that an in-plane magnetic field induces a photocurrent linearly proportional to the magnetic field; however, a magnetic field tilted to the sample plane induces a photocurrent presenting quadratic magnetic field dependence. The magneto-photocurrents in both conditions are insensitive to the polarization state of the incident light. Theoretical models involving excitation, relaxation and Hall effect are utilized to explain the experimental results.
    Nanoscale Research Letters 01/2014; 9(1):279. DOI:10.1186/1556-276X-9-279 · 2.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We study the tunneling of conduction electrons through a (110)-oriented single-barrier heterostructure grown from III-V semiconductor compounds. It is shown that, due to low spatial symmetry of such a barrier, the tunneling current through the barrier leads to an electron spin polarization. The inverse effect, generation of a direct tunneling current by spin polarized electrons, is also predicted. We develop the microscopic theory of the effects and show that the spin polarization emerges due to the combined action of the Dresselhaus spin-orbit coupling within the barrier and the Rashba spin-orbit coupling at the barrier interfaces.
    Physical Review B 01/2014; 89(15). DOI:10.1103/PhysRevB.89.155306 · 3.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The paper reviews the interplay of Rashba/Dresselhaus spin splittings in various two-dimensional systems made of zinc-blende III–V, wurtzite, and SiGe semiconductors. We discuss the symmetry aspects of the linear and cubic in electron wavevector spin splitting in heterostructures prepared on (001)-, (110)-, (111)-, (113)-, (112)-, and (013)- oriented substrates and address the requirements for suppression of spin relaxation and realization of the persistent spin helix state. In experimental part of the paper, we overview experimental results on the interplay of Rashba/Dresselhaus spin splittings probed by photogalvanic spectroscopy: The method based on the phenomenological equivalence of the linear-in-wavevector spin splitting and several photogalvanic phenomena.
    physica status solidi (b) 09/2014; 251(9). DOI:10.1002/pssb.201350261 · 1.61 Impact Factor

Full-text (2 Sources)

Download
55 Downloads
Available from
May 27, 2014