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Schwerpunktprogramm SPP 1285
Halbleiter Spintronik
Spintronik > Projekte > Projektansicht

Projekt

Ansprechpartner1
Dr. Saskia F. Fischer
Adresse1

Ruhr-Universität Bochum
Lehrstuhl für Werkstoffe und Nanoelektronik
Universitätsstraße 150
Gebäude IC 2
44780 Bochum

Tel.:
Tel.:(0234) 32 25760
Fax:
Fax:(0234) 32 14166
Ansprechpartner2
Prof. Dr. Ulrich Kunze
Adresse2

Ruhr-Universität Bochum
Lehrstuhl für Werkstoffe und Nanoelektronik
Universitätsstraße 150
Gebäude IC 2
44780 Bochum

Tel.:
Tel.:(0234) 32 22300
Fax:
Fax:(0234) 32 14166
Projekttitel
Spin-dependant electron transport in GaAs/AlGaAs nanostructures
Projektbeschreibung

The aim of this project is to investigate spin-dependent ballistic transport in nanoscale GaAs/AlGaAs field-effect heterostructures. Starting materials are modulation doped heterostructures with two-dimensional electron gases of high mobilities (> 106 cm2/Vs) from which Aharonov-Bohm ring structures are defined by electron-beam lithography and wetchemical etching. Local top and side gates will be used to control the electron densities in the electron wave guides of the ring. Four-terminal measurements of current and voltage characteristics will be taken as a function of top and side gate voltages and magnetic fields at low temperatures (less 4.2 K). Injection of spin polarized electrons in the ring is planned by using a quantum point contact with ultra-large subband separations (>10 meV) as spin filter element in inplane magnetic fields. The amplitude and phase of the Aharonov-Bohm conductance oscillations will be measured for different operating modes of the injecting quantum point contact. Up-to-date, the transport in the mode occupation below the first mode of a quantum point contact is discussed with spin-related mechanisms and remains an unresolved issue. The long-term goal is the investigation of spin-related dephasing mechanisms in the electronic quantum transport by adding a single-electron transistor with tunable coupling to the ring structure.

Zurück

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)