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Related papers: Optical spin orientation and depolarization in Ge

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The dynamics of magnetization under femtosecond optical excitation is studied in a ferromagnetic semiconductor Ga_{0.94}Mn_{0.06}As with a time-resolved magneto-optical Kerr effect measurement with two color probe beams. The transient…

Strongly Correlated Electrons · Physics 2009-11-07 E. Kojima , R. Shimano , Y. Hashimoto , S. Katsumoto , Y. Iye , M. Kuwata-Gonokami

Spin-polarized scanning tunneling microscopy investigations reveal a significant increase of the magnetic period of spin spirals in three-atomic-layer-thick Fe films on Ir(111), from about 4nm at 8K to about 65nm at room temperature. We…

Mesoscale and Nanoscale Physics · Physics 2017-07-26 Aurore Finco , Levente Rózsa , Pin-Jui Hsu , André Kubetzka , Elena Vedmedenko , Kirsten von Bergmann , Roland Wiesendanger

Electrically generated spin polarization is probed directly in bulk GaN using Kerr rotation spectroscopy. A series of n-type GaN epilayers are grown in the wurtzite phase both by molecular beam epitaxy (MBE) and metalorganic chemical vapor…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 W. F. Koehl , M. H. Wong , C. Poblenz , B. Swenson , U. K. Mishra , J. S. Speck , D. D. Awschalom

A hight degree of spin polarization is achieved for a Mn atom localized in a semiconductor quantum dot using quasi-resonant optical excitation at zero magnetic field. Optically created spin polarized carriers generate an energy splitting of…

Other Condensed Matter · Physics 2012-06-18 C. Le Gall , L. Besombes , H. Boukari , R. Kolodka , H. Mariette , J. Cibert

Spin-polarized electron photoemission has been studied for GaAs/GaAs$_{1-x}$P$_x$ strained superlattice cathodes grown by gas-source molecular beam epitaxy. The superlattice structural parameters are systematically varied to optimize the…

Instrumentation and Detectors · Physics 2009-11-10 T. Maruyama , D. -A. Luh , A. Brachmann , J. E. Clendenin , E. L. Garwin , S. Harvey , J. Jiang , R. E. Kirby , C. Y. Prescott , R. Prepost , A. M. Moy

It has been shown by Fano (1969) https://doi.org/10.1103/PhysRev.178.131 that photoionization of a c{\ae}sium atom by a laser pulse tuned to the vicinity of a Cooper minimum generates spin-polarized electrons. Here we show that while…

Understanding and manipulating spin polarization and transport in the vicinity of semiconductor-hosted defects is a problem of present technological and fundamental importance. Here, we use high-field magnetic resonance to monitor the…

Mesoscale and Nanoscale Physics · Physics 2014-01-14 Yunpu Li , Jonathan P. King , Jeffrey A. Reimer , Carlos A. Meriles

We measure the spin-resolved transport of dipolar excitons in a biased GaAs double quantum well structure. From these measurements we extract both spin lifetime and mobility of the excitons. We find that below a temperature of $4.8$K, there…

Optical absorption of circularly polarized light is well known to yield an electron spin polarization in direct band gap semiconductors. We demonstrate that electron spins can even be generated with high efficiency by absorption of linearly…

The longest spin lifetimes in bulk n-GaAs exceed 100 ns for doping concentrations near the metal-insulator transition (J.M. Kikkawa, D.D. Awschalom, Phys. Rev. Lett. 80, 4313 (1998)). The respective electronic states have yet not been…

Materials Science · Physics 2007-06-14 L. Schreiber , M. Heidkamp , T. Rohleder , B. Beschoten , G. Güntherodt

Optical properties of dislocations free state-of-the-art Germanium(Ge) and Germanium-oninsulator(GeOI) wafers have been characterized using Fourier transformed infrared spectroscopy at oblique incidence, attenuated total reflectance, laser…

Mesoscale and Nanoscale Physics · Physics 2015-12-29 S. Kalem , I. Romandic , A. Theuwis

Rydberg excitons, characterized by large spatial extension and reduced electron-hole overlap, must have a spin-valley dynamics different from that of ground state excitons. Here we report a direct measurement of spin relaxation of Rydberg…

Other Condensed Matter · Physics 2026-04-09 V. Jindal , K. Mourzidis , M. Semina , D. Lagarde , A. Balocchi , P. Renucci , T. Boulier , T. Taniguchi , K. Watanabe , M. Glazov , X. Marie

The helicity of a circularly polarized light beam may be determined by the spin direction of photo-excited electrons in a III-V semiconductor. We present a theoretical demonstration how the direction of the ensuing electron spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 H. Dery , L. Cywinski , L. J. Sham

We present results of a cross-disciplinary theoretical research at the interface of spin physics and hot-electron transport. A moderately strong electric field is assumed to provide the streaming regime where each free charge carrier, an…

Mesoscale and Nanoscale Physics · Physics 2014-04-29 L. E. Golub , E. L. Ivchenko

We have measured the terahertz response of oriented germanium nanowires using ultrafast optical-pump terahertz-probe spectroscopy. We present results on the time, frequency, and polarization dependence of the terahertz response. Our results…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Jared H. Strait , Paul A. George , Mark Levendorf , Martin Blood-Forsythe , Farhan Rana , Jiwoong Park

The wide bandgap semiconductor ZnO is interesting for spintronic applications because of its small spin-orbit coupling implying a large spin coherence length. Utilizing vertical spin valve devices with ferromagnetic electrodes…

We have studied experimentally and theoretically the optical orientation and spin-dependent Shockley-Read-Hall recombination in a semiconductor in a magnetic field at an arbitrary angle between the field and circularly polarized exciting…

Mesoscale and Nanoscale Physics · Physics 2016-09-21 E. L. Ivchenko , L. A. Bakaleinikov , M. M. Afanasiev , V. K. Kalevich

Electrical spin injection into semiconductors paves the way for exploring new phenomena in the area of spin physics and new generations of spintronic devices. However the exact role of interface states in spin injection mechanism from a…

Optical orientation experiments have been performed in GaAs epilayers with photoexcitation energies in the 3 eV region yielding the photogeneration of spin-polarized electrons in the satellite L valley. We demonstrate that a significant…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 T. Zhang , P. Barate , C. T. Nguyen , A. Balocchi , T. Amand , P. Renucci , H. Carrere , B. Urbaszek , X. Marie

We exploit the influence of the Coulomb interaction between electrons and holes on the electron spin relaxation in a (110)-GaAs quantum well to unveil excitonic signatures within the many particle electron-hole system. The temperature…

Mesoscale and Nanoscale Physics · Physics 2011-04-07 S. Oertel , S. Kunz , D. Schuh , W. Wegscheider , J. Hübner , M. Oestreich