  We demonstrate a new method for electrical manipulation of nuclear spins
utilizing dynamic nuclear polarization induced by quantum Hall effect
breakdown. Nuclear spins are polarized and detected through the hyperfine
interaction between a nuclear spin system and a two-dimensional electron system
located at an interface of GaAs/AlGaAs single heterostructure. Coherent
oscillations between the nuclear-spin quantum states are observed by measuring
the longitudinal voltage of the conductor.
