Search arXiv⌕ Search

arXiv · cond-mat/0607627

Transport and recombination through weakly coupled localized spin pairs in semiconductors during coherent spin excitation

Abstract

Semi-analytical predictions for the transients of spin-dependent transport and recombination rates through localized states in semiconductors during coherent electron spin excitation are made for the case of weakly spin-coupled charge carrier ensembles. The results show that the on-resonant Rabi frequency of electrically or optically detected spin-oscillation doubles abruptly as the strength of the resonant microwave field gamma B_1 exceeds the Larmor frequency separation within the pair of charge carrier states between which the transport or recombination transition takes place. For the case of a Larmor frequency separation of the order of gamma B_1 and arbitrary excitation frequencies, the charge carrier pairs exhibit four different nutation frequencies. From the calculations, a simple set of equations for the prediction of these frequencies is derived.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

V. Rajevac, C. Boehme, C. Michel, A. Gliesche, K. Lips, S. D. Baranovski, P. Thomas. 2006-07-25. Transport and recombination through weakly coupled localized spin pairs in semiconductors during coherent spin excitation. https://doi.org/10.1103/physrevb.74.245206

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Nanoscale Inclined Four-electrode Ion Traps: Finite-Element Modelling, Floquet Stability, and Surface-Potential Response

Developing miniaturised trapped-ion systems requires electrode architectures that provide controlled radio-frequency (RF) confinement while accounting for nanoscale features and surface-induced perturbations. Here, we present a finite-element investigation of an inclined four-blade RF ion-trap architecture for 171Yb+, combining pseudopotential characterisation, matrix Mathieu analysis, Floquet stability assessment, and localised surface-potential modelling. The architecture incorporates exposed electrode-face features of approximately 99-150 nm within an opposing-electrode separation of 20 um. At an electrode inclination of 6 degrees, an RF amplitude of 150 V, and a drive frequency of 15 MHz, the calculated pseudopotential exhibits directional in-plane barriers of 3.430 and 3.389 meV along the principal diagonal paths. The full RF-potential Hessian, including off-diagonal coupling terms, is used to construct the matrix Mathieu equation. Numerical propagation over one RF period identifies two dominant motional branches with secular-frequency estimates of 1.8137 and 1.8181 MHz. A third, predominantly axial branch exhibits a nominal frequency near 7.90 kHz, although its quantitative resolution is limited by the residual Hessian trace and phase-return drift. Additionally, a four-source electrostatic model is developed to investigate the effects of localised surface potentials on modal electric-field responses. Parametric analysis reveals correlation-dependent suppression and enhancement of normalised response coefficients, with multipliers ranging from approximately 0.5 to 1.5. This study establishes a computational framework for investigating nanoscale inclined blade-electrode architectures, their motional characteristics, and surface-potential responses, while highlighting numerical convergence requirements for reliable three-dimensional trap characterisation.

cond-mat.other↗

Chiral-vibration-induced magnetism and circular dichroism in organic molecules

We investigate the vibrational inverse Faraday effect and transient vibrational circular dichroism in benzene, coronene, and methane at the single-molecule level. We combine density-functional tight-binding calculations with damped normal-mode dynamics. Circularly polarized light excites suitable degenerate infrared-active modes, driving chiral nuclear motion that produces effective magnetic moments. Reversing the pump helicity reverses the vibrational chirality and the sign of the transient dichroic response. These results support a writing-readout scheme in which circularly polarized pumping prepares a chiral vibrational state and transient vibrational circular dichroism probes its handedness. We further examine how molecular symmetry shapes the light-induced chiral response across the three molecular systems. This work provides a valuable platform for exploring all-optical control of magnetism and chiroptical probing at the molecular scale.

cond-mat.other↗

A Construction Framework for Three-Dimensional Topological Magnetic Textures

Three-dimensional magnetic systems offer diverse possibilities for constructing complex topological textures from simpler magnetic configurations. Here, we present different routes for constructing complex three-dimensional magnetic textures from simpler parent configurations and discuss their impact on the topology of the resulting structures. We identify four construction principles: (i) adding transverse modulations, (ii) adding structures, (iii) entangling textures (e.g. braiding, or twisting), and (iv) introducing singularities. Using the skyrmion tube as an explicit parent configuration, we show how these principles give rise to several known three-dimensional magnetic textures. We then apply the same principles to predict novel textures derived from a meron tube, which are confirmed by micromagnetic simulations to be metastable in chiral magnets. Our results establish general principles for the systematic construction and discovery of complex three-dimensional magnetic textures.

cond-mat.other↗