Superconducting phase transitions in frustrated Josephson-junction arrays on a dice lattice
| Autor: | Young-Je Yun, In-Cheol Baek, M. Choi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Physics
Josephson effect Superconductivity Condensed matter physics Statistical Mechanics (cond-mat.stat-mech) media_common.quotation_subject Condensed Matter - Superconductivity Monte Carlo method Energy Engineering and Power Technology Frustration FOS: Physical sciences Tourbillon Condensed Matter Physics Classical XY model Electronic Optical and Magnetic Materials Vortex Superconductivity (cond-mat.supr-con) Lattice (order) Electrical and Electronic Engineering Condensed Matter - Statistical Mechanics media_common |
| Popis: | Transport measurements are carried out on dice Josephson-junction arrays with the frustration index $f=1/3$ and 1/2 which possess, within the limit of the $XY$ model, an accidental degeneracy of the ground states as a consequence of the formation of zero-energy domain walls. The measurements demonstrate that both the systems undergo a phase transition to a superconducting vortex-ordered state at considerably high temperatures. The experimental findings are in apparent contradiction with the theoretical expectation that frustration effects in the $f=1/3$ system are particularly strong enough to suppress a vortex-ordering transition down to near zero temperature. The data for $f=1/2$ are more consistent with theoretical evaluations. The agreement between the experiments and the Monte Carlo simulations of a $XY$ model for $f=1/3$ suggests that the order-from-disorder mechanism for the removal of an accidental degeneracy may still be effective in the $f=1/3$ system. The transport data also reveal that the dice arrays with zero-energy domain walls experience a much slower critical relaxation than other frustrated arrays only with finite-energy walls. 4 pages, 4 figures |
| Databáze: | OpenAIRE |
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