Issue
EPL
Volume 83, Number 4, August 2008
Article Number 47005
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/83/47005
Published online 04 August 2008
EPL, 83 (2008) 47005
DOI: 10.1209/0295-5075/83/47005

Gauge symmetry breaking and topological quantization for the Pauli Hamiltonian

E. Medina1, 2, A. López1 and B. Berche2

1  Centro de Física, Instituto Venezolano de Investigaciones Científicas - Apartado 21874, Caracas 1020-A, Venezuela
2  Laboratoire de Physique des Matériaux, Université Henri Poincaré, Nancy 1 - 54506 Vandoeuvre les Nancy Cedex, France, EU

ernestomed@gmail.com

received 7 May 2008; accepted in final form 25 June 2008; published August 2008
published online 4 August 2008

Abstract
We discuss the Pauli Hamiltonian within a SU(2) gauge theory interpretation, where the gauge symmetry is broken. This interpretation carries directly over to the structural inversion asymmetric spin-orbit interactions in semiconductors and offers new insight into the problem of spin currents in the condensed-matter environment. The central result is that symmetry breaking leads to zero spin conductivity in contrast to predictions of gauge symmetric treatments. Computing the translation operator commutation relations comprising the simplest possible structural inversion asymmetry due to an external electric field, we derive a new condition for orbit quantization. The relation between the topological nature of this effect is consistent with our non-Abelian gauge symmetry breaking scenario.

PACS
71.70.Ej - Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect.
72.25.-b - Spin polarized transport.
73.43.Nq - Quantum phase transitions .

© EPLA 2008