Giant lasing effect in magnetic nanoconductors

TL;DR

This paper introduces a novel mechanism for a compact solid-state laser operating in the 1-100 THz range, utilizing giant lasing effects in magnetic nanoconductors through spin-flip processes induced by light-electron interactions.

Contribution

It proposes a new laser principle based on spin-flip processes in ferromagnetic conductors, achieving high optical gain and operating in a challenging THz frequency range.

Findings

Predicted giant lasing effect in ferromagnetic conductors.

Estimated optical gain exceeds conventional semiconductor lasers.

Laser frequency range of 1-100 THz based on experimental data.

Abstract

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 till 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 10^7 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.