Parity effect and charge binding transition in submicron Josephson junction arrays
Feigel'man M.V., Korshunov S.E., Pugachev A.B.
We reconsider the issue of Berezinskii-Kosterlitz-Thouless (BKT) transition into an insulating state in the Coulomb-dominated Josephson junction arrays. We show that previously predicted picture of the Cooper-pair BKT transition at X ôÇ is valid only under the condition that Ti is considerably below the parity-effect temperature T* « 0.1Δ and even in this case it is not a rigorous phase transition but only a crossover, whereas the real phase transition takes place at T\ sa ΤΊ/4. Our theory is in agreement with available experimental data on Coulomb-dominated Josephson arrays and also sheds some light on the origin of unusual reentrant temperature dependence of resistivity in the array with nearly-criticial ratio Ec/Ej. PACS: 73.23.Hk, 74.50.+ç, 74.80.Dm