Nernst effect as a signature of quantum fluctuations in quasi-one-dimensional superconductors

We study a model for the transverse thermoelectric response due to quantum superconducting fluctuations in a two-leg Josephson ladder, subject to a perpendicular magnetic field B and a transverse temperature gradient. Assuming a weak Josephson coupling on the rungs, the off-diagonal Peltier coefficient (α_xy) and the Nernst effect are evaluated as functions of B and the temperature T. In this regime, the Nernst effect is found to exhibit a prominent peak close to the superconductor-insulator transition, which becomes progressively enhanced at low T. In addition, we derive a relation to the diamagnetic response α_xy=-M/T₀, where M is the equilibrium magnetization and T₀ a plasma energy in the superconducting legs.