Giant lasing effect in magnetic nanoconductors
Artikel i vetenskaplig tidskrift, 2004

We propose a new principle for a compact solid-state laser in the 1–100 THz regime. This is a frequency range where attempts to fabricate small-size lasers up to now have met severe technical problems. The proposed laser is based on a new mechanism for creating spin-flip processes in ferromagnetic conductors. The mechanism is due to the interaction of light with conduction electrons; the interaction strength, being proportional to the large exchange energy, exceeds the Zeeman interaction by orders of magnitude. On the basis of this interaction, a giant lasing effect is predicted in a system where a population inversion has been created by tunneling injection of spin-polarized electrons from one ferromagnetic conductor to another—the magnetization of the two ferromagnets having different orientations. Using experimental data for ferromagnetic manganese perovskites with nearly 100% spin polarization, we show the laser frequency to be in the range 1–100 THz. The optical gain is estimated to be of order 107 cm−1, which exceeds the gain of conventional semiconductor lasers by 3 or 4 orders of magnitude. A relevant experimental study is proposed and discussed.

solid lasers

ferromagnetic materials

magnetic tunnelling


electron spin polarisation

population inversion


Anatoli M. Kadigrobov

Göteborgs universitet

Zdravko Ivanov

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Tord Claeson

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Robert I. Shekhter

Göteborgs universitet

Mats Jonson

Chalmers, Teknisk fysik, Kondenserade materiens teori

Europhysics Letters

0295-5075 (ISSN) 1286-4854 (eISSN)

Vol. 67 6 948-954





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