Persistent current generation by a Berry phase

We consider a persistent current generation by the fictitious magnetic field generated by spin-vortices in a solid with two-dimensional conduction layers. Each center of the spin-vortices is a singularity that imposes the sign-change boundary condition on the wavefunction for the conduction electron. We handle the sign-change boundary condition by introducing a fictitious magnetic field and show that loop currents are generated by it even in the ground state. Actually, a distribution of NV singularities causes the ground state to be -fold degenerate with different current patterns. When an external magnetic field is applied, this degeneracy is partly lifted and the one that expels the magnetic field is chosen. This response strongly resembles the Meissner effect seen in superconductors. The flux quantization also occurs with the unit h/2e as in superconductors.

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