Modelling of Optical Detection of Spin-Polarized Carrier Injection into Light-Emitting Devices

We investigate the emission of multimodal polarized light from Light Emitting Devices due to spin-aligned carriers injection. The results are derived through operator Langevin equations, which include thermal and carrier-injection fluctuations, as well as non-radiative recombination and electronic g-factor temperature dependence. We study the dynamics of the optoelectronic processes and show how the temperature-dependent g-factor and magnetic field affect the polarization degree of the emitted light. In addition, at high temperatures, thermal fluctuation reduces the efficiency of the optoelectronic detection method for measuring spin-polarization degree of carrier injection into non-magnetic semicondutors.Comment: 15 pages, 7 figures, replaced by revised version. To appear in Phys. Rev.

Optical Properties of III-Mn-V Ferromagnetic Semiconductors

We review the first decade of extensive optical studies of ferromagnetic, III-Mn-V diluted magnetic semiconductors. Mn introduces holes and local moments to the III-V host, which can result in carrier mediated ferromagnetism in these disordered semiconductors. Spectroscopic experiments provide direct access to the strength and nature of the exchange between holes and local moments; the degree of itineracy of the carriers; and the evolution of the states at the Fermi energy with doping. Taken together, diversity of optical methods reveal that Mn is an unconventional dopant, in that the metal to insulator transition is governed by the strength of the hybridization between Mn and its p-nictogen neighbor. The interplay between the optical, electronic and magnetic properties of III-Mn-V magnetic semiconductors is of fundamental interest and may enable future spin-optoelectronic devices.Comment: Topical Revie

Spin dynamics in semiconductors

This article reviews the current status of spin dynamics in semiconductors which has achieved a lot of progress in the past years due to the fast growing field of semiconductor spintronics. The primary focus is the theoretical and experimental developments of spin relaxation and dephasing in both spin precession in time domain and spin diffusion and transport in spacial domain. A fully microscopic many-body investigation on spin dynamics based on the kinetic spin Bloch equation approach is reviewed comprehensively.Comment: a review article with 193 pages and 1103 references. To be published in Physics Reports

Temperature dependences of the structural and the mechanical properties of a CdMnCrTe quaternary alloy

We investigated the structural and the mechanical properties of single crystals of the diluted magnetic semiconductor (DMS) Cd1−x−yMnxCryTe (x = 0.37, 0 ??? y ??? 0.03) grown by using the vertical Bridgman method. High-temperature X-ray diffraction (XRD) and microhardness measurements were carried out during heating processes at temperatures from room temperature to 750 K. The lattice constants increased with increasing temperature whereas the lattice constants decreased with increasing Cr composition y. The hardness of the Cd1−x−yMnxCryTe crystal increased exponentially with decreasing temperature for T ??? 600 K, and it remained constant for T ??? 700 K. The Vickers hardness, HV, decreased with increasing temperature and increased with increasing Cr composition y. The activation energy for the dislocation motion was determined from the relation between temperature and hardness.ope