Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 91: Poster Session: Spintronics / Magnetic Semiconductors / Transport
HL 91.6: Poster
Thursday, March 29, 2012, 16:00–19:00, Poster D
Evidence for an efficient dynamical nuclear polarization process in a high-mobility (110)-grown two-dimensional electron system — •M. Griesbeck1, B. Erbe1, M. Glazov2, E. Sherman3, T. Korn1, D. Schuh1, W. Wegscheider4, J. Schliemann1, and C. Schüller1 — 1Department of Physics, Regensburg University, Germany — 2Ioffe Physical-Technical Institute, St. Petersburg, Russia — 3Department of Physical Chemistry, The University of the Basque Country, Bilbao, Spain — 4Solid State Physics Laboratory, ETH Zürich, Switzerland
As a consequence of the limited electron spin lifetime, the intensively studied concept of dynamical nuclear polarization (DNP) using two-dimensional electron gases still lacks an experimental implementation [1]. Recently, the spin dephasing time along the growth direction in (110)-grown zinkblende-based heterostructures, especially in symmetrically grown and doped two-dimensional electron systems, has been demonstrated to reach extremely high values [2]. By means of the all-optical resonant spin amplification technique [3], we study the anisotropic spin dynamics. Our sample consists of a 30 nm wide double-sided δ-doped single quantum well with a very high mobility of about 3 million cm2/Vs. At low temperatures, we find evidence for a very efficient DNP process. We clearly map the expected strong dependence of the DNP on the initial spin polarization of the electron system.
[1] I. Ţifrea and M. Flatté, Phys. Rev. B 84, 155319 (2011)
[2] M. Griesbeck et al., preprint: http://arxiv.org/abs/1111.5438
[3] J. M. Kikkawa et al., Phys. Rev. Lett. 80, 4313 (1998)