Electrostatic interface tuning in correlated superconducting heterostructures

TL;DR

This paper investigates how electrostatic fields influence high-temperature superconducting films, revealing that interface effects can localize charge and induce a superconductor-insulator transition, impacting the phase diagram.

Contribution

It introduces a model considering electric dipoles and phonons at the interface, explaining electrostatic tuning effects in HTSC heterostructures.

Findings

Electrostatic fields can localize injected charge via interface coupling.

Charge localization leads to a superconductor-insulator transition.

Phase diagram modifications are significant near and above optimal doping.

Abstract

An electrostatic field, which is applied to a gated high-temperature superconducting (HTSC) film, is believed to affect the film similar to charge doping. Analyzing the pairing in terms of a t-J model, we show that a coupling to electric dipoles and phonons at the interface of film and dielectric gate localizes the injected charge and leads to a superconductor-insulator transition. This results in a dramatic modification of the doping dependent phase diagram close to and above the optimal doping which is expected to shed light on recent electric field-effect experiments with HTSC cuprates.