Europhys. Lett.
Volume 66, Number 6, June 2004
Page(s) 826 - 832
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 June 2004
Europhys. Lett., 66 (6) , pp. 826-832 (2004)
DOI: 10.1209/epl/i2003-10263-3

Quantum beating in ring conductance: Observation of spin chiral states and Berry's phase

M. J. Yang1, C. H. Yang2 and Y. B. Lyanda-Geller1

1  Naval Research Laboratory - Washington, DC 20375, USA
2  Department of Electrical and Computer Engineering University of Maryland - College Park, MD 20742, USA

(Received 29 October 2003; accepted in final form 15 April 2004)

We propose and demonstrate experimentally a novel configuration for observing spin interference effects in mesoscopic rings. Using this configuration, in which the conducting ring and the tangential current lead form a single collimating contact, we have observed the spin quantum beating in the Aharonov-Bohm conductance oscillations. We demonstrate that the beating is the result of the superposition of two independent interference signals associated with two orthogonal states arising from intrinsic spin-orbit interactions. Our work demonstrates the signature of the spin Berry phase in the conductance of quantum rings.

73.63.Nm - Quantum wires.
73.23.Ad - Ballistic transport.
73.40.Kp - III-V semiconductor-to-semiconductor contacts, p- n junctions, and heterojunctions.

© EDP Sciences 2004