TUNABLE BISTABLE HYSTERESIS OF THE MAGNETIC-RESONANCE OF CONDUCTION ELECTRONS IN SOLIDS

Under dynamic nuclear polarisation by the Overhauser effect, conductio n electrons in solids can exhibit a hysteresis of their magnetic reson ance. In the case of polycrystalline samples of beta-Ga2O3, a giant hy steresis can be achieved corresponding to a situation where the electr on spins absorb the electromagnetic field when the magnetic field is s wept downward and no absorption occurs in the reverse sweep direction. It is shown that this phenomenon is a general property of conducting solids containing elements with non-zero nuclear spins.