Quantum phase transition in an array of coupled superconducting quantum dots with charge frustration

Abstract

We present the quantum phase transition in two capacitively coupled arrays of superconducting quantum dots (SQD). We consider the presence of gate voltage in each superconducting island. We show explicitly that the co-tunneling process involves with two coupled SQD arrays, near the maximum charge frustration line is not sufficient to explain the correct quantum phases with physically consistent phase boundaries. We consider another extra co-tunneling process along each chain to explain the correct quantum phases with physically consistent phase boundaries. There is no evidence of supersolid phase in our study. We use Bethe-ansatz and Abelian bosonization method to solve the problem