2002/09/30 by T. K. Kopec, T. K. Kopeć, T. P. Polak · 1 citation
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.66.094517
published as Phys. Rev. B 66, 094517 (2002), see http://prb.aps.org/ · 9 pages, 8 figures
openalex publication_date 2002/09/30 · arxiv created 2003/01/14 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study a quantum Hamiltonian that models a two-dimensional array of Josephson junctions with short-range Josephson couplings (given by the Josephson energy EJ) and the charging energy EC---due to the small capacitance of the junctions. We include effects from both the self-C0 and the junction-C1 capacitances in the presence of an external magnetic flux f=\ensuremathΦ/\ensuremathΦ0, as well as uniform background of charges qx. We derive an effective quantum nonlinear \ensuremathσ model for the array Hamiltonian, which enables us a non-mean-field treatment of the zero-temperature phase transition. We calculate the ground-state phase diagram, analytically deriving EJcrit(EC,qx,f) for several rational fluxes f=0, (1)/(2), (1)/(3), (1)/(4), and (1)/(6), which improves upon previous theoretical treatments.