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Related papers: Spin-Exchange Interaction in ZnO-based Quantum Wel…

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Spin-orbit coupling (SOC) is pivotal for various fundamental spin-dependent phenomena in solids and their technological applications. In semiconductors, these phenomena have been so far studied in relatively weak electron-electron…

Mesoscale and Nanoscale Physics · Physics 2021-06-09 D. Maryenko , M. Kawamura , A. Ernst , V. K. Dugaev , E. Ya. Sherman , M. Kriener , M. S. Bahramy , Y. Kozuka , M. Kawasaki

We calculate Heisenberg-type magnetic exchange interactions for SrMnO$_3$ under isotropic volume expansion using an approach that is based on total energy variations due to infinitesimal spin rotations around a given reference state. Our…

Materials Science · Physics 2020-02-12 Xiangzhou Zhu , Alexander Edström , Claude Ederer

The expression of the thermal fluctuation parameter in the stochastic Landau-Lifshitz-Gilbert equation has been derived from a fundamental quantum theory of spins and phonons, in which the exchange interaction between nearest atoms has been…

Mesoscale and Nanoscale Physics · Physics 2015-01-21 Lei Xu , Dan Wei , Kuijuan Jin , Zhongshui Ma

We have measured dispersions of spin-flip waves and spin-flip single-particle excitations of a spin polarized two-dimensional electron gas in a CdMnTe quantum well using resonant Raman scattering. We find the energy of the spin-flip wave to…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Cynthia Aku-Leh , Florent Perez , Bernard Jusserand , David Richards , Grzegorz Karczewski

The Heisenberg exchange interaction between neighboring quantum dots allows precise voltage control over spin dynamics, due to the ability to precisely control the overlap of orbital wavefunctions by gate electrodes. This allows the study…

We have observed a large spin splitting between "spin" $+1$ and $-1$ heavy-hole excitons, having unbalanced populations, in undoped GaAs/AlAs quantum wells in the absence of any external magnetic field. Time-resolved photoluminescence…

Condensed Matter · Physics 2016-08-31 L. Vina , L. Munoz , E. Perez , J. Fernandez-Rossier , C. Tejedor , K. Ploog

We use time-resolved Kerr rotation to demonstrate the optical and electronic tuning of both the electronic and local moment (Mn) spin dynamics in electrically gated parabolic quantum wells derived from II-VI diluted magnetic semiconductors.…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 R. C. Myers , K. C. Ku , X. Li , N. Samarth , D. D. Awschalom

Coulomb exchange interactions of electrons in the nu=3 quantum Hall state are determined from two inter-Landau level spin-flip excitations measured by resonant inelastic light scattering. The two coupled collective excitations are linked to…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 A. B. Van'kov , T. D. Rhone , A. Pinczuk , I. V. Kukushkin , L. N. Pfeiffer , K. W. West

The Quantum Zeno Effect (QZE) implies that a too frequent ($\omega_\phi \to \infty)$ observation of a quantum system would trap it in its initial state, even though it would be able to evolve to some other state if not observed. In our…

Strongly Correlated Electrons · Physics 2009-10-30 Horacio M. Pastawski , Gonzalo Usaj

We show by spatially and time-resolved photoluminescence that the application of an electric field transverse to the plane of an intrinsic GaAs (111) quantum well (QW) allows the transport of photogenerated electron spins polarized along…

Mesoscale and Nanoscale Physics · Physics 2019-03-13 A. Hernández-Mínguez , K. Biermann , R. Hey , P. V. Santos

The utility of nanoscaled ferromagnetic particles requires both stabilized moments and maximized switching speeds. During reversal, the spatial modulation of the nanoparticle magnetization evolves in time, and the energy differences between…

Co-doped ZnO is the prototypical dilute magnetic oxide showing many of the characteristics of ferromagnetism. The microscopic origin of the long range order however remains elusive, since the conventional mechanisms for the magnetic…

Materials Science · Physics 2015-05-18 Thomas Archer , Chaitanya Das Pemmaraju , Stefano Sanvito

The exchange interaction among electrons is one of the most fundamental quantum mechanical interactions in nature and underlies any magnetic phenomena from ferromagnetic ordering to magnetic storage. The current technology is built upon a…

Materials Science · Physics 2015-05-20 G. P. Zhang , M. S. Si , Y. H. Bai , Thomas F. George

We report on the unusual and counter-intuitive behaviour of spin lifetime of excitons in coupled semiconductor quantum wells (CQWs) in the presence of in-plane magnetic field. Instead of conventional acceleration of spin relaxation due to…

We report on the consequences of non-uniform exchange in magnetic systems. The quantum mechanical exchange interaction between spins is responsible for the phenomenon of magnetic order, and is generally considered to be uniform across bulk…

Materials Science · Physics 2021-09-22 Rair Macêdo , Arjun S. Kudinoor , Karen L. Livesey , Robert E. Camley

Electronic states and the Aharonov-Bohm effect in ZnO quantum dot-ring nanostructures containing few interacting electrons reveal several unique features. We have shown here that in contrast to the dot-rings made of conventional…

Mesoscale and Nanoscale Physics · Physics 2018-03-14 Tapash Chakraborty , Aram Manaselyan , Manuk Barseghyan

A scattering mechanism stemming from the Stark-shift of energy levels by electric fields in semiconductor quantum wells is identified. This scattering mechanism feeds off interface roughness and electric fields, and modifies the well known…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 Raj K. Jana , Debdeep Jena

A system of two quantum wells (QW), one made of HgCdTe and the other of HgCdMnTe, subjected to electric and magnetic fields $F$ and $B$ parallel to the growth direction, is proposed and described theoretically. It is shown that in such a…

Materials Science · Physics 2012-06-21 Pawel Pfeffer , Wlodek Zawadzki

The theory of spin relaxation of conduction electrons is developed for zinc-blende-type quantum wells grown on (110)-oriented substrate. It is shown that, in asymmetric structures, the relaxation of electron spin initially oriented along…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 S. A. Tarasenko

The results of magnetoconductivity measurements in GaInAs quantum wells are presented. The observed magnetoconductivity appears due to the quantum interference, which lead to the weak localization effect. It is established that the details…