BGU Physics Department

Colloquium, Oct. 14, 2010

Spin-orbit in ballistic semiconductor

David Goldhaber, Stanford University

Understanding the flow of spins in magnetic layered structures has resulted in an increase in data storage density in hard
drives over the past decade of more than two orders of magnitude. Following this remarkable success, the field of 'spintronics’ or
spin-based electronics is moving beyond effects based on local spin polarization and is turning towards spin–orbit interaction (SOI)
effects, which hold promise for the production, detection and manipulation of spin currents, allowing coherent transmission of
information within a device. Although SOI-induced spin transport effects have been observed in two- and three-dimensional samples,
these have been subtle and elusive, often detected only indirectly in electrical transport or else with more sophisticated techniques. I
will discuss the experimental observation of a predicted ‘spin–orbit gap’ in a one-dimensional sample, where counter-propagating spins,
constituting a spin current, are accompanied by a clear signal in the easily measured linear conductance of the system.

Journal reference: Observation of a one-dimensional spin–orbit gap in
a quantum wire
C. H. L. Quay, T. L. Hughes, J. A. Sulpizio, L. N. Pfeiffer, K. W.
Baldwin, K. W. West, D. Goldhaber-Gordon, R. de Picciotto
Nature Physics (21 March 2010) doi:10.1038/nphys1626 Letter