Related papers: Theory of Weak Localization in Ferromagnetic (Ga,M…
We report experimental and theoretical studies of magnetic domain walls in an in-plane magnetized (Ga,Mn)As dilute moment ferromagnetic semiconductor. Our high-resolution electron holography technique provides direct images of domain wall…
Some of the highest transition temperatures achieved for Mn-doped GaAs have been in delta-doped heterostructures with well-separated planes of Mn. But in the absence of magnetic anisotropy, the Mermin-Wagner theorem implies that a single…
After two decades from the discovery of ferromagnetism in Mn-doped GaAs, its origin is still debated, and many doubts are related to the electronic structure. Here we report an experimental and theoretical study of the valence electron…
We report the measurements and analysis of weak antilocalization (WAL) in Pb1-xSnxSe topological quantum wells in a new regime where the elastic scattering length is larger than the magnetic length. We achieve this regime through the…
We demonstrated the control of ferromagnetism in a surface quantum well containing a 5-nm-thick n-type ferromagnetic semiconductor (In,Fe)As layer sandwiched between two InAs layers, by manipulating the carrier wavefunction. The Curie…
We put forward a theory of the weak localization in two dimensional graphene layers which explains experimentally observable transition between positive and negative magnetoresistance. Calculations are performed for the whole range of…
Although InP and GaAs have very similar band-structure their magnetic properties appear to drastically differ. Critical temperatures in (In,Mn)P are much smaller than that of (Ga,Mn)As and scale linearly with Mn concentration. This is in…
We use the local density approximation (LDA) and LDA+U schemes to study the magnetism of (GaMn)As and (GaMn)N for a number of Mn concentrations and varying number of holes. We show that for both systems and both calculational schemes the…
Magnetic properties of Mn-doped GaAs are re-investigated within a realistic multiband description of the host valence bands. We explicitely demonstrate that the recent Monte Carlo (MC) simulations performed on a large scale supercomputer…
We demonstrate that in ferromagnetic Ga1-xMnxP exchange is mediated by holes localized in a Mn-derived band. For x<0.06, infrared absorption and photoconductivity spectra indicate the presence of a Mn impurity band which is not merged with…
The nonlinear transport regime is manifested in the nonlinear current-voltage characteristic of the system. An example of such a nonlinear regime is a setup in which current is injected into the sample and the measured voltage drop is…
We report on the results of investigation the conductivity and magnetoresistance (MR) temperature dependencies for the two strained multilayer p-type Ge/Ge_{1-x}Si_x heterostructures. The usual logarithmic temperature dependencies for zero…
Semiconductor structures using ferromagnetic semiconductors as spin injectors are promising systems for future spintronic devices. Here, we present combined photoluminescence (PL) and time-resolved magneto-optical experiments of a nominally…
We show that suitably-designed magnetic semiconductor heterostructures consisting of Mn delta-doped GaAs and p-type AlGaAs layers, in which the locally high concentration of magnetic moments of Mn atoms are controllably overlapped with the…
We have performed magnetoresistance measurements on polyfluorene sandwich devices in weak magnetic fields as a function of applied voltage, device temperature (10K to 300K), film thickness and electrode materials. We observed either…
Magnetic properties of (Ga,Mn)As/GaAs superlattices are investigated. The structures contain magnetic (Ga,Mn)As layers, separated by thin layers of non-magnetic GaAs spacer. The short period Ga$_{0.93}$Mn$_{0.07}$As/GaAs superlattices…
In chalcogenide topological insulator materials, two types of magneto-resistance (MR) effects are widely discussed: a positive MR dip around zero magnetic field associated with the weak antilocalization (WAL) effect and a linear MR effect…
We utilize a single atom substitution technique with spectroscopic imaging in a scanning tunneling microscope (STM) to visualize the anisotropic spatial structure of magnetic and non-magnetic transition metal acceptor states in the GaAs…
Measurements of coherent electron spin dynamics in Ga(1-x)Mn(x)As/Al(0.4)Ga(0.6)As quantum wells with 0.0006% < x < 0.03% show an antiferromagnetic (negative) exchange bewteen s-like conduction band electrons and electrons localized in the…
We investigate the interference correction to the conductivity of a medium consisting of metallic grains connected by tunnel junctions. Tunneling conductance between the grains, $e^2g_{\rm T}/\pi\hbar$, is assumed to be large, $g_{\rm T}\gg…