  Properties of a Nuclear-Spin-Polarization-Induced Quantum Ring (NSPI QR) are
studied theoretically. In the proposed system a local nuclear spin polarization
creates an effective hyperfine field which confines the electrons with the
spins opposite to the hyperfine field to the regions of maximal nuclear spin
polarization. We investigate the electron energy spectrum and the magnetic
response of NSPI QR and their evolution in time due to the nuclear spin
diffusion and relaxation.
