Topological Order in the Insulating Josephson Junction Array
Abstract
We propose a Josephson junction array which can be tuned into an unconventional insulating state by varying external magnetic field. This insulating state retains a gap to half-vortices; as a consequence, such an array with nontrivial global geometry exhibits a ground state degeneracy. This degeneracy is protected from the effects of external noise. We compute the gaps, separating higher energy states from the degenerate ground state, and we discuss experiments probing the unusual properties of this insulator.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2003
- DOI:
- 10.1103/PhysRevLett.90.107003
- arXiv:
- arXiv:cond-mat/0211146
- Bibcode:
- 2003PhRvL..90j7003D
- Keywords:
-
- 74.81.Fa;
- 03.67.Lx;
- 85.25.Cp;
- 85.25.Hv;
- Josephson junction arrays and wire networks;
- Quantum computation;
- Josephson devices;
- Superconducting logic elements and memory devices;
- microelectronic circuits;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Superconductivity
- E-Print:
- 4 pages, RevTex 4, 1 EPS figure