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Related papers: Fast optical control of spin in semiconductor inte…

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Optical control of spin in semiconductors has been pioneered using nanostructures of III-V and II-VI semiconductors, but the emergence of two-dimensional van der Waals materials offers an alternative low-dimensional platform for spintronic…

Coherent interactions between spins in quantum dots are a key requirement for quantum gates. We have performed pump-probe experiments in which pulsed lasers emitting at different photon energies manipulate two distinct subsets of electron…

Mesoscale and Nanoscale Physics · Physics 2011-10-03 S. Spatzek , A. Greilich , Sophia E. Economou , A. Schwan , S. Varwig , D. R. Yakovlev , D. Reuter , A. D. Wieck , T. L. Reinecke , M. Bayer

The authors study the ultrafast switching-on and -off of planar GaAs/AlAs microcavities. Up to 0.8% refractive index changes are achieved by optically exciting free carriers at 1720 nm and a pulse energy of 1.8 micro Joules. The cavity…

Coherent manipulation of quantum bits (qubits) on time scales much shorter than the coherence time is a key prerequisite for quantum information processing. Electron spins in quantum dots (QDs) are particularly attractive for…

Mesoscale and Nanoscale Physics · Physics 2011-10-03 A. Greilich , Sophia E. Economou , S. Spatzek , D. R. Yakovlev , D. Reuter , A. D. Wieck , T. L. Reinecke , M. Bayer

Spin-polarized transport of photo-electrons in bulk, p-type GaAs is investigated in the Pauli blockade regime. In contrast to usual spin diffusion processes in which the spin polarization decreases with distance traveled due to spin…

Mesoscale and Nanoscale Physics · Physics 2013-12-17 F. Cadiz , D. Paget , A. C. H. Rowe

We advance spin noise spectroscopy to an ultrafast tool to resolve high frequency spin dynamics in semiconductors. The optical non-demolition experiment reveals the genuine origin of the inhomogeneous spin dephasing in n-doped GaAs wafers…

Mesoscale and Nanoscale Physics · Physics 2010-04-22 Georg M. Müller , Michael Römer , Jens Hübner , Michael Oestreich

Spins in semiconductor quantum dots are promising local quantum memories to generate polarization-encoded photonic cluster states, as proposed in the pioneering Rudolph-Lindner scheme [1]. However, harnessing the polarization degree of…

Mesoscale and Nanoscale Physics · Physics 2023-11-28 N. Coste , M. Gundin , D. Fioretto , S. E. Thomas , C. Millet , E. Medhi , M. Gundin , N. Somaschi , M. Morassi , M. Pont , A. Lemaitre , N. Belabas , O. Krebs , L. Lanco , P. Senellart

Electron spin polarizations of 32% are obtained in a GaAs quantum well via electrical injection through a reverse-biased Fe/AlGaAs Schottky contact. An analysis of the transport data using the Rowell criteria demonstrates that single step…

Measurements and modeling of electron spin transport and dynamics are used to characterize hyperfine interactions in Fe/GaAs devices with $n$-GaAs channels. Ga and As nuclei are polarized by electrically injected electron spins, and the…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 M. K. Chan , Q. O. Hu , J. Zhang , T. Kondo , C. J. Palmstrøm , P. A. Crowell

We report measurements and calculations of the spin-subband depopulation, induced by a parallel magnetic field, of dilute GaAs two-dimensional (2D) hole systems. The results reveal that the shape of the confining potential dramatically…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 R. Winkler , E. Tutuc , S. J. Papadakis , S. Melinte , M. Shayegan , D. Wasserman , S. A. Lyon

Similar to light polarization that is selected by a superposition of optical basis, electron spin direction can be controlled through a superposition of spin basis. We investigate such a spin interference occurring in photoemission of the…

Materials Science · Physics 2022-03-16 Kenta Kuroda , Koichiro Yaji , Ryo Noguchi , Ayumi Harasawa , Shik Shin , Takeshi Kondo , Fumio Komori

We investigate site-controlled In$_{0.25}$Ga$_{0.75}$As quantum dots in (111)B GaAs pyramidal recesses as spin qubits. Combining scanning confocal cryomicroscopy, magneto-photoluminescence studies and resonant excitation, we identify and…

Mesoscale and Nanoscale Physics · Physics 2025-09-09 R. A. Barcan , I. Samaras , K. Barr , G. Juska , E. Pelucchi , K. G. Lagoudakis

Spin defects in silicon carbide have exceptional electron spin coherence with a near-infrared spin-photon interface in a material amenable to modern semiconductor fabrication. Leveraging these advantages, we successfully integrate highly…

Spin-orbit coupling in semiconductors relates the spin of an electron to its momentum and provides a pathway for electrically initializing and manipulating electron spins for applications in spintronics and spin-based quantum information…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 V. Sih , R. C. Myers , Y. K. Kato , W. H. Lau , A. C. Gossard , D. D. Awschalom

A compact cryogenic Kerr microscope for operation in the small volume of high-field magnets is described. It is suited for measurements both in Voigt and Faraday configuration. Coupled with a pulsed laser source, the microscope is used to…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 P. J. Rizo , A. Pugžlys , J. Liu , D. Reuter , A. D. Wieck , C. H. van der Wal , P. H. M. van Loosdrecht

We use helicity-resolved ultrafast transient absorption spectroscopy to study spin-valley polarization dynamics in a vertically stacked MoSe$_{2}$/WSe$_{2}$ heterostructure. The experimental findings reveal details of interlayer charge…

The mean squared value of the photonic disorder is found to be reduced by a factor of 100 in a typical GaAs based microcavity, when exposed to a circularly polarized continuous wave optical pump without any special spatial patterning.…

Mesoscale and Nanoscale Physics · Physics 2011-04-12 T. C. H. Liew , V. Savona

Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to…

We show that the spin-charge separation predicted for correlated fermions in one dimension, could be observed using polarized photons propagating in a nonlinear optical waveguide. Using coherent control techniques and employing a cold atom…

Quantum Physics · Physics 2012-08-01 Ming-Xia Huo , Dimitris G. Angelakis , Leong Chuan Kwek

In the field of spin-controlled semiconductor lasers, massive effort has been focused upon materials with long spin relaxation times (~ns). In contrast, we demonstrate room-temperature spin-polarized ultrafast pulsed lasing in InGaAs…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Feng-kuo Hsu , Yi-Shan Lee , Sheng-Di Lin , Chih-Wei Lai