Patent ID: 8593724

Claim:
A four-level magnon laser comprising: a ferromagnetic material having a conduction band that is split into two sub bands, a first said subband having spin up (along the direction of magnetization of said ferromagnetic material), and a second said subband having spin down (opposite to the direction of magnetization of said ferromagnetic material), and said ferromagnetic material further comprising: a four-level laser structure further comprising: a lowest energy level corresponding to a valence band; a highest energy level corresponding to a spin-down subband; a second intermediate energy level corresponding to a spin-up subband; wherein electrons from said lowest energy level pumped into said highest energy level move into the lower energy electron states in said spin -up subband, and wherein said pumped electrons emit magnons; and a first intermediate level corresponding to said lower energy electron states in said spin-up subband; and wherein said second intermediate energy level is placed in said energy space lower than said first intermediate level; and wherein said electrons in said spin-up subband move into the bottom of said spin-up subband by using an energy relaxation mechanism selected form the group consisting of: {emission of optical phonons; and electron-electron interaction}; and wherein said electrons are pumped from said lowest energy level into said highest energy level by using a pumping means.