Quantum phase transitions in superconducting arrays under external magnetic fields
Abstract
We study the zero-temperature phase transitions of two-dimensional superconducting arrays with both the self- and the junction capacitances in the presence of external magnetic fields. We consider two kinds of excitations from the Mott insulating phase: charge-dipole excitations and single-charge excitations, and apply the second-order perturbation theory to find their energies. The resulting phase boundaries are found to depend strongly on the magnetic frustration, which measures the commensurate-incommensurate effects. Comparison of the obtained values with those in recent experiment suggests the possibility that the superconductor-insulator transition observed in experiment may not be of the Berezinskii-Kosterlitz-Thouless type. The system is also transformed to a classical three-dimensional XY model with the magnetic field in the time-direction; this allows the analogy to bulk superconductors, revealing the nature of the phase transitions.
Cite
@article{arxiv.cond-mat/9810221,
title = {Quantum phase transitions in superconducting arrays under external magnetic fields},
author = {Beom Jun Kim and Gun Sang Jeon and M. -S. Choi and M. Y. Choi},
journal= {arXiv preprint arXiv:cond-mat/9810221},
year = {2007}
}
Comments
9 pages including 7 figures, to appear in Phys. Rev. B