相关论文: Light and electric field control of ferromagnetism…
We predict that the Curie temperature of a ferromagnetic resonant tunneling diode will decrease abruptly, by approximately a factor of two, when the downstream chemical potential falls below the quantum well resonance energy. This property…
We propose a ferromagnetic/ferroelectric hybrid double quantum well structure, and present an investigation of the Curie temperature (Tc) modulation in this quantum structure. The combined effects of applied electric fields and spontaneous…
We demonstrate electrical control of ferromagnetism in field-effect transistors with a trilayer quantum well (QW) channel containing an ultrathin n-type ferromagnetic semiconductor (In,Fe)As layer. A gate voltage is applied to control the…
We demonstrate the electrical and optical control of ferromagnetism in semiconductor heterostructures at high temperatures of 100-117 K. The heterostructures consist of Mn delta-doped GaAs and p-type AlGaAs, where the overlap of the hole…
Ferromagnetism is predicted in undoped diluted magnetic semiconductors illuminated by intense sub-bandgap laser radiation . The mechanism for photo-induced ferromagnetism is coherence between conduction and valence bands induced by the…
We predict bistability in the Curie temperature-voltage characteristic of double barrier resonant-tunneling structures with dilute ferromagnetic semiconductor quantum wells. Our conclusions are based on simulations of electrostatics and…
A (II,Mn)VI diluted magnetic semiconductor quantum dot with an integer number of electrons controlled with a gate voltage is considered. We show that a single conduction band electron is able to induce a spontaneous collective magnetization…
A review is given of advances in the field of carrier-controlled ferromagnetism in Mn-based diluted magnetic semiconductors and their nanostructures. Experimental results for III-V materials, where the Mn atoms introduce both spins and…
A density functional theory of ferromagnetism in heterostructures of compound semiconductors doped with magnetic impurities is presented. The variable functions in the density functional theory are the charge and spin densities of the…
We show that the critical temperature of a ferromagnetic phase transition in a quasi-two-dimensional hole gas confined in a diluted magnetic semiconductor quantum well strongly depends on the hole chemical potential and hole density. The…
Cr$_2$B displays temperature independent paramagnetism. We induce ferromagnetism by replacing less than $3\,\%$ of the Cr atoms by Fe. By the lowest Fe doping level made, Curie-Weiss behavior is observed; $\Theta_{CW}$ changes from $-20\,$K…
The infinite-dimensional Hubbard model is studied by means of a modified perturbation theory. The approach reduces to the iterative perturbation theory for weak coupling. It is exact in the atomic limit and correctly reproduces the…
A mean field model of ferromagnetism mediated by delocalized or weakly localized holes in zinc-blende and wurzite diluted magnetic semiconductors is presented. The model takes into account: (i) strong spin-orbit and kp couplings in the…
We analyze the heat current traversing a quantum dot sandwiched between a ferromagnetic and a superconducting electrode. The heat flow generated in response to a voltage bias presents rectification as a function of the gate potential…
To understand the halfmetallic ferromagnet EuB6 we use the Kondo lattice model for valence and conduction band. By means of a recently developed many-body theory we calculate the electronic properties in the ferromagnetic regime up to the…
We present theoretical studies of temperature dependent diamagnetic-paramagnetic transitions in thin quantum rings. Our studies show that the magnetic susceptibility of metal/semiconductor rings can exhibit multiple sign flips at…
The temperature dependence of the electronic structure of CeBi arising from two types of antiferromagnetic transitions based on optical conductivity ($\sigma(\omega)$) was observed. The $\sigma(\omega)$ spectrum continuously and…
The Hubbard model on fcc-type lattices is studied in the dynamical mean-field theory of infinite spatial dimensions. At intermediate interaction strength finite temperature Quantum Monte Carlo calculations yield a second order phase…
We present the manipulation of magnetic and electrical properties of (Ga,Mn)As by the adsorption of dye-molecules as a first step towards the realization of light-controlled magnetic-semiconductor/dye hybrid devices. A significant lowering…
We report on the observation of the Ising quantum Hall ferromagnet with Curie temperature $T_C$ as high as 2 K in a modulation-doped (Cd,Mn)Te heterostructure. In this system field-induced crossing of Landau levels occurs due to the giant…