Europhys. Lett.
Volume 69, Number 4, February 2005
Page(s) 595 - 601
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 21 January 2005
Europhys. Lett., 69 (4), pp. 595-601 (2005)
DOI: 10.1209/epl/i2004-10395-x

How many electrons are needed to flip a local spin?

W. Kim, R. K. Teshima and F. Marsiglio

Theoretical Physics Institute and Department of Physics, University of Alberta Edmonton, Alberta, Canada, T6G 2J1

received 9 November 2004; accepted 16 December 2004
published online 21 January 2005

Considering the spin of a local magnetic atom as a quantum-mechanical operator, we illustrate the dynamics of a local spin interacting with a ballistic electron represented by a wave packet. This approach improves the semi-classical approximation and provides a complete quantum-mechanical understanding for spin transfer phenomena. Sending spin-polarized electrons towards a local magnetic atom one after another, we estimate the minimum number of electrons needed to flip a local spin.

72.25.-b - Spin polarized transport.
73.23.Ad - Ballistic transport.
73.63.-b - Electronic transport in nanoscale materials and structures.

© EDP Sciences 2005