Low Temperature Physics: 37, 925 (2011); https://doi.org/10.1063/1.3671676 (8 pages)
Fizika Nizkikh Temperatur: Volume 37, Number 11 (November 2011), p. 1163-1172 ( to contents , go back )
Microwave-induced spin-flip scattering of electrons in point contacts
A.M. Kadigrobov1,2, R.I. Shekhter1, I. Aronov3, S.I. Kulinich1,4, A. Pulkin1, and M. Jonson1,5,6
1 Department of Physics, University of Gothenburg, SE-412 96 Göteborg, Sweden
2 Theoretische Physik III, Ruhr-Universität Bochum, D-44801 Bochum, Germany
3 2366 Wilderness Way, Marietta, GA 30066, USA
4 B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
5 SUPA, Department of Physics, Heriot-Watt University, Edinburgh EH14 4AS, Scotland, UK
6 Division of Quantum Phases and Devices, School of Physics, Konkuk University, Seoul 143-701, Korea
Received April 5, 2011
We investigate resonant interaction of conduction electrons with an electromagnetic field that irradiates a point contact between a ferromagnetic and a normal metal in the presence of a strong magnetic field of order 1 T. We show that electron spin-flips caused by resonant absorption and stimulated emission of photons result in a sharp peak in the magnetic-field dependence of the point-contact resistance. The height of the peak is shown to be directly proportional to the net rate of energy transfer to the electromagnetic field in the point contact due to absorption and stimulated emission of photons. Estimations indicate that our theory can serve as a basis for the explanation of recent experiments [A.M. Kadigrobov et al., New J. Phys. 13, 023007 (2011)].
PACS: 72.25.–b Spin polarized transport;
Key words: point-contact spectroscopy, hot electrons, stimulated photon emission, spin-polarized injection.