title: Subwavelength terahertz spin-flip laser based on a magnetic point-contact array.
abstract: We present a theoretical design for a single-mode, truly subwavelength terahertz disk laser based on a nanocomposite gain medium comprising an array of normal-metal/ferromagnetic (FM) point contacts embedded in a thin dielectric layer. Stimulated emission of light occurs due to spin-flip relaxation of spin-polarized electrons injected from the FM side of the contacts. Ultrahigh electrical current densities in the contacts and a dielectric material with a large refractive index, neither condition being achievable in conventional semiconductor media, enables the thresholds of lasing to be overcome for the lowest-order modes of the disk, making single-mode operation possible.
authors.affiliation: Department of Physics, University of Gothenburg, SE-412 96 Göteborg, Sweden.
authors.forename: Robert I
authors.initials: RI
authors.lastname: Shekhter
authors.forename: Anatoliy M
authors.initials: AM
authors.lastname: Kadigrobov
authors.forename: Mats
authors.initials: M
authors.lastname: Jonson
authors.forename: Elena I
authors.initials: EI
authors.lastname: Smotrova
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Nosich
authors.forename: Vladislav
authors.initials: V
authors.lastname: Korenivski