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Schwerpunktprogramm SPP 1285
Halbleiter Spintronik
Spintronik > Projekte > Projektansicht


Prof. Dr. Alexander W. Holleitner

Technische-Universität München
Walter Schottky Institut
Am Coulombwall 3
85748 Garching

Tel.:089/289 12775
Fax:089/320 6620
Optoelectronic Detection of Non-Equilibrium Spin Transport in the Mesoscopic Regime in Semiconductor Nanostructures

A mesoscopic spin detector shall be lithographically built to detect an optically induced spin population in a two-dimensional electron reservoir of a semiconductor heterostructure. The optoelectronic spin detector shall exploit spin-split one-dimensional subbands of a quantum wire and it shall explore mesoscopic spin-transport phenomena of a non-equilibrium spin population in the diffusive and the ballistic regime. Particular emphasize will be placed on spin scattering processes at the transition from a two-dimensional to a onedimensional system. By orienting the spin detector along different crystallographic directions, we furthermore expect insights into spin relaxation mechanisms induced by spin-orbit coupling terms, i.e. due to structural and bulk inversion asymmetry. The proposed spin detector shall prepare ground for an optoelectronic spin device, which exploits the specific non-linearity in the current-voltage characteristics and the one-dimensional density of states of a quantum wire. To this end, the mesoscopic spin detector shall be optoelectronically characterized as a function of photon wavelength, polarization, source/drain voltage, external magnetic field, and temperature. In order to photo-excite the spin population, an ultra-short, pulsed, wavelength-tunable laser system will be used. The tunability allows measuring the photo-conductance close to the absorption edge of the lowdimensional electron system, while a pulsed laser system offers the possibility to define electron spin packages for spinelectronic time-of-flight experiments. 2. State of the Art, Preliminary Work


Wichtige Termine:

15. Sept. 2013:
Deadline für den Sonderband Semiconductor Spintronics (DFG-Abschlussbericht) in physica status solidi b
(nähere Informationen wurden per Email zugeschickt)

30. Sept. - 2. Okt. 2013:
Abschlusstreffen des Schwerpunktprogramms "International workshop on semiconductor spintronics" in der Residenz Würzburg
(nähere Informationen)

Aktuelle Veröffentlichung(en):

C. Drexler, S.A. Tarasenko, P. Olbrich, J. Karch, M. Hirmer, F. Müller, M. Gmitra, J. Fabian, R. Yakimova, S. Lara-Avila, S. Kubatkin, M. Wang, R. Vajtai, P. M. Ajayan, J. Kono, and S.D. Ganichev :  "Magnetic quantum ratchet effect in graphene" Nature Nanotechnology 8, 104 (2013)

J.H. Buß, J. Rudolph, S. Shvarkov, H. Hardtdegen, A.D. Wieck, and D. Hägele:  "Long electron spin coherence in ion‐implanted GaN: The role of localization" Appl. Phys. Lett. 102, 192102 (2013)

D.J. English, J. Hübner, P.S. Eldridge, D. Taylor, M. Henini, R.T. Harley, and M. Oestreich:  "Effect of symmetry reduction on the spin dynamics of (001)-oriented GaAs quantum wells" Phys. Rev. B 87, 075304 (2013)

V.L. Korenev, I.A. Akimov, S.V. Zaitsev, V.F. Sapega, L. Langer, D.R. Yakovlev, Yu. A. Danilov, and M. Bayer:  "Dynamic spin polarization by orientation-dependent separation in a ferromagnet–semiconductor hybrid" Nature Communications 3, 959 (2012)

M. Althammer, E.-M. Karrer-Müller, S.T.B. Goennenwein, M. Opel, R. Gross:  "Spin transport and spin dephasing in zinc oxide" Appl. Phys. Lett. 101, 082404 (2012)