# A high-temperature superconducting weak-link defined by ferroelectric field-effect

## TL;DR

This paper demonstrates how ferroelectric domain patterns in BiFeO3 can be used to create and control weak links in high-temperature superconducting YBa2Cu3O7, enabling local modulation of superconductivity for device applications.

## Contribution

It introduces a method to define superconducting weak links using ferroelectric domain engineering in oxide bilayers, enabling local control of superconductivity.

## Key findings

- Ferroelectric domain patterns modulate superconductivity in YBa2Cu3O7.
- Device exhibits Josephson-like weak-link behavior.
- Potential for high-temperature superconducting device fabrication.

## Abstract

In all-oxide ferroelectric (FE) - superconductor (S) bilayers, due to the low carrier concentration of oxides compared to transition metals, the FE interfacial polarization charges induce an accumulation (or depletion) of charge carriers in the S. This leads either to an enhancement or a depression of its critical temperature depending on FE polarization direction.Here we exploit this effect at a local scale to define planar weak-links in high-temperature superconducting wires. This is realized in BiFeO3(FE)/YBa2Cu3O7(S)bilayers in which the remnant FE domain structure is written at will by locally applying voltage pulses with a conductive-tip atomic force microscope. In this fashion, the FE domain pattern defines a spatial modulation of superconductivity. This allows us to write a device whose electrical transport shows different temperature regimes and magnetic field matching effects that are characteristic of Josephson coupled weak-links. This illustrates the potential of the ferroelectric approach for the realization of high-temperature superconducting devices.

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Source: https://tomesphere.com/paper/1703.01219