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Related papers: Antiferromagnetic s-d exchange coupling in GaMnAs

200 papers

Higher order quantum effects on the magnetic phase diagram induced by four-spin ring exchange on plaquettes are investigated for a two-dimensional quantum antiferromagnet with S=1/2. Spatial anisotropy and frustration are allowed for. Using…

Superconductivity · Physics 2015-06-04 Kingshuk Majumdar , Douglas Furton , Goetz S. Uhrig

We propose the two-band s-d model to describe theoretically a diffuse regime of the spin-dependent electron transport in magnetic tunnel junctions (MTJ's) of the form F/O/F where F's are 3d transition metal ferromagnetic layers and O is the…

Materials Science · Physics 2009-11-07 D. Bagrets , A. Bagrets , A. Vedyayev , B. Dieny

The Fermi level position in (Ga,Mn)N has been determined from the period-analysis of GaN-related Franz-Keldysh oscillation obtained by contactless electroreflectance in a series of carefully prepared by molecular beam epitaxy…

Materials Science · Physics 2017-12-19 L. Janicki , G. Kunert , M. Sawicki , E. Piskorska-Hommel , K. Gas , R. Jakiela , D. Hommel , R. Kudrawiec

We review recent experimental results indicating the band flattening and Landau level merging at the chemical potential in strongly-correlated two-dimensional (2D) electron systems. In ultra-clean, strongly interacting 2D electron system in…

Strongly Correlated Electrons · Physics 2022-09-22 V. T. Dolgopolov , M. Yu. Melnikov , A. A. Shashkin , S. V. Kravchenko

We theoretically study the effect of exchange interaction on the non-equilibrium spin waves in disordered paramagnetic metals under the spin injection condition. We show that the gapless spectrum of spin waves, describing the spin…

Mesoscale and Nanoscale Physics · Physics 2010-07-29 A. A. Zyuzin , A. Yu. Zyuzin

We complete our earlier (Phys. Rev. B, {\bf 66}, 134435 (2002)) study of the electronic structure, exchange interactions and Curie temperature in (GaMn)As and extend the study to two other diluted magnetic semiconductors (GaCr)As and…

Materials Science · Physics 2009-11-10 L. M. Sandratskii , P. Bruno

We investigated optical spin orientation and dynamic nuclear polarization (DNP) in individual self-assembled InGaAs/GaAs quantum dots (QDs) doped by a single Mn atom, a magnetic impurity providing a neutral acceptor A$^0$ with an effective…

Mesoscale and Nanoscale Physics · Physics 2016-11-15 O. Krebs , E. Baudin , A. Lemaître

We measure the effective mass (m*) of interacting two-dimensional electrons confined to a 4.5 nm-wide AlAs quantum well. The electrons in this well occupy a single out-of-plane conduction band valley with an isotropic in-plane Fermi…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 T. Gokmen , Medini Padmanabhan , K. Vakili , E. Tutuc , M. Shayegan

Surface spin waves in the short-wavelength regime enable ultrafast, nanoscale magnon-based devices. Here we report the emergence of surface spin-wave excitations within the bulk magnon band gap of type-A van der Waals antiferromagnets…

Mesoscale and Nanoscale Physics · Physics 2025-05-01 Zhoujian Sun , Fuxiang Li , Gerrit E. W. Bauer , Ping Tang

We report measurements of dm/dn in Si MOSFET, where m is the magnetization of the two-dimensional electron gas and n is its density. We extended the density range of measurements from well in the metallic to deep in the insulating region.…

Strongly Correlated Electrons · Physics 2011-03-08 M. Reznikov , A. Yu. Kuntsevich , N. Teneh , V. M. Pudalov

Inelastic neutron scattering is used to identify single-particle and continuum spin excitations in the quasi-one-dimensional $S=1/2$ antiferromagnet \ba. In the data analysis, close attention is given to resolution effects. A gap in the…

Strongly Correlated Electrons · Physics 2007-05-23 A. Zheludev , M. Kenzelmann , S. Raymond , T. Masuda , K. Uchinokura , S. -H. Lee

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 electron spin resonance spectrum of a quasi 1D S=1/2 antiferromagnet K2CuSO4Br2 was found to demonstrate an energy gap and a doublet of resonance lines in a wide temperature range between the Curie--Weiss and Ne\`{e}l temperatures. This…

Strongly Correlated Electrons · Physics 2015-10-28 A. I. Smirnov , T. A. Soldatov , K. Yu. Povarov , M. Hälg , W. E. A. Lorenz , A. Zheludev

Weak antilocalization is studied in an InGaAs quantum well. Anomalous magnetoresistance is measured and described theoretically in fields perpendicular, tilted and parallel to the quantum well plane. Spin and phase relaxation times are…

Mesoscale and Nanoscale Physics · Physics 2010-12-30 G. M. Minkov , A. V. Germanenko , O. E. Rut , A. A. Sherstobitov , L. E. Golub , B. N. Zvonkov , M. Willander

We report on the exchange biasing of self-assembled ferromagnetic GeMn nanocolumns by GeMn-oxide caps. The x-ray absorption spectroscopy analysis of this surface oxide shows a multiplet fine structure that is typical of the Mn2+ valence…

We report on magnetotransport measurements in two MBE-grown GaAs/AlGaAs superlattices formed by wide and narrow quantum wells and thin Si-doped barriers subject to tilted magnetic fields. It has been shown that illumination of the strongly…

Mesoscale and Nanoscale Physics · Physics 2011-05-05 L. Smrcka , N. A. Goncharuk , P. Svoboda , P. Vasek , Yu. Krupko , W. Wegscheider

A five-level {\Pp} model of the band structure for GaAs-type semiconductors is used to describe the spin $g^*$-factor and the cyclotron mass $m^*_c$ of conduction electrons in GaAs/Ga$_{1-x}$Al$_x$As quantum wells in an external magnetic…

Materials Science · Physics 2009-11-11 P. Pfeffer , W. Zawadzki

We study the kinetics of spin coherence of optically excited electrons in an undoped insulating ZnSe/Zn$_{1-x}$Cd$_x$Se quantum well under moderate magnetic fields in the Voigt configuration. After clarifying the optical coherence and the…

Condensed Matter · Physics 2009-10-31 M. W. Wu , H. Metiu

Diluted magnetic semiconductors (DMS) like Ga$_{1-x}$Mn$_{x}$As are described by a realistic tight-binding model (TBM) for the (valence) bands of GaAs, by a Zener (J-)term modeling the coupling of the localized Mn-spins to the spins of the…

Strongly Correlated Electrons · Physics 2014-04-09 Stefan Barthel , Gerd Czycholl , Georges Bouzerar

We study the interaction-enhanced spin gaps in the two-dimensional electron gas confined in GaAs/AlGaAs single heterojunctions subjected to weak magnetic fields. The values are obtained from the chemical potential jumps measured by…

Strongly Correlated Electrons · Physics 2007-05-23 V. S. Khrapai , A. A. Shashkin , E. L. Shangina , V. Pellegrini , F. Beltram , G. Biasiol , L. Sorba