TY - JOUR

T1 - Finite-size-scaling analyses of the chiral order in the Josephson-junction ladder with half a flux quantum per plaquette

AU - Nishiyama, Yoshihiro

PY - 2000/9/2

Y1 - 2000/9/2

N2 - Chiral order of the Josephson-junction ladder with half a flux quantum per plaquette is studied by means of the exact diagonalization method. We consider an extreme quantum limit where each superconductor grain (order parameter) is represented by S = 1/2 spin. So far, the semi-classical S → ∞ case, where each spin reduces to a plane rotator, has been considered extensively. We found that in the case of S = 1/2, owing to the strong quantum fluctuations, the chiral (vortex lattice) order becomes dissolved except in a region, where attractive intrachain and, to our surprise, repulsive interchain interactions both exist. On the contrary, for considerably wide range of parameters, the superconductor (XY) order is kept critical. The present results are regarded as a demonstration of the critical phase accompanying chiral-symmetry breaking predicted for frustrated XXZ chain field-theoretically.

AB - Chiral order of the Josephson-junction ladder with half a flux quantum per plaquette is studied by means of the exact diagonalization method. We consider an extreme quantum limit where each superconductor grain (order parameter) is represented by S = 1/2 spin. So far, the semi-classical S → ∞ case, where each spin reduces to a plane rotator, has been considered extensively. We found that in the case of S = 1/2, owing to the strong quantum fluctuations, the chiral (vortex lattice) order becomes dissolved except in a region, where attractive intrachain and, to our surprise, repulsive interchain interactions both exist. On the contrary, for considerably wide range of parameters, the superconductor (XY) order is kept critical. The present results are regarded as a demonstration of the critical phase accompanying chiral-symmetry breaking predicted for frustrated XXZ chain field-theoretically.

KW - 75.10.Jm Quantized spin models

KW - 75.40.Mg Numerical simulation studies

KW - 85.25.Cp Josephson devices

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U2 - 10.1007/s100510070144

DO - 10.1007/s100510070144

M3 - Article

AN - SCOPUS:0001247221

SN - 1434-6028

VL - 17

SP - 295

EP - 299

JO - European Physical Journal B

JF - European Physical Journal B

IS - 2

ER -