Spin Meissner effect in superconductors and the origin of the Meissner effect

J. E. Hirsch

doi:doi:10.1209/0295-5075/81/67003

EPL, 81 (2008) 67003
DOI: 10.1209/0295-5075/81/67003

Spin Meissner effect in superconductors and the origin of the Meissner effect

J. E. Hirsch

Department of Physics, University of California, San Diego - La Jolla, CA 92093-0319, USA

received 9 January 2008; accepted in final form 30 January 2008; published March 2008
published online 28 February 2008

Abstract
We propose a dynamical explanation of the Meissner effect in superconductors and predict the existence of a spin Meissner effect: that a macroscopic spin current flows within a London penetration depth $\lambda _{L}$ of the surface of superconductors in the absence of applied external fields, with carrier density = the superfluid density and carrier speed $v=\hbar /(4m_{e}\lambda_{L})$ (m_e= bare electron mass). The two members of a Cooper pair circulate in orbits of radius $2\lambda _{L}$ in opposite direction and the spin current in a Cooper pair has orbital angular momentum $\hbar$ . Our description also provides a "geometric" interpretation of the difference between type-I and type-II superconductors.

PACS
74.20.-z - Theories and models of superconducting state.
74.20.Mn - Nonconventional mechanisms (spin fluctuations, polarons and bipolarons, resonating valence bond model, anyon mechanism, marginal Fermi liquid, Luttinger liquid, etc.).
71.70.Ej - Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect .

© EPLA 2008