2 00 1 Enhancement of Nuclear Spin Superradiance by Electron Resonator 1

Superradiance of nuclear spins is considered, when the nuclei interact via hyperfine forces with electrons of a ferromagnet. The consideration is based on a microscopic model. If the sample, coupled with a resonant electric circuit, possesses electronic magnetization, then the electron subsystem plays the role of an additional effective resonator, by enhancing the coupling between nuclear spins and the resonant circuit. Radiation power can be increased by three orders, while the radiation time of a superradiance burst can become three times shorter. In the presence of dynamic nuclear polarization, the regime of pulsing superradiance can occur. Invited report at the International Workshop on Laser Physics, Bordeaux (2000). 1