CONTROL METHOD FOR FERROMAGNETIC RESONANCE FREQUENCY USING CARRIER INDUCING FERROMAGNETIC MATERIAL AND FREQUENCY FILTER ELEMENT USING IT

摘要

PROBLEM TO BE SOLVED: To provide a frequency filter capable of modulating a resonant frequency by control from outside.;SOLUTION: The frequency filter element comprises a multi-layer structure where an insulating layer 3 composed of i-AlGaAs is laminated on a conductive substrate 1 composed of n⁺-GaAs, and then a thin film 5 of a ferromagnetic semiconductor (semiconductor in which Mn, a magnetic metal, is doped to GaAs) Ga_1-xMn_xAs layer is laminated on top of it. Magnetization M is turned in a specific direction using magnetic anisotropy peculiar to GaMnAs. An insulating film 7 is formed to the GaMnAs layer 5. A metallic electrode 11 for field application is formed on the insulating film 7. Microwaves are radiated to the element. When a electric field vector is parallel to magnetization (orthogonal to magnetic field), it combines with magnetization. When the electric field vector is orthogonal to magnetization, it does not combine with magnetization. A control means for controlling a carrier density can adjust a resonant frequency ω determined by external magnetic field/magnetization/anisotropy constants.;COPYRIGHT: (C)2006,JPO&NCIPI