Reversible Superconductivity in Electrochromic Indium-Tin Oxide Films

TL;DR

This study demonstrates reversible electrochromic superconductivity in indium-tin-oxide films through electrochemical intercalation, enabling tunable superconducting and optical properties with potential applications in transparent electronics.

Contribution

It introduces a method to reversibly induce and control superconductivity in ITO films via electrochemical intercalation, combining optical transparency with superconducting functionality.

Findings

Superconductivity in ITO films can be reversibly tuned by electrochemical intercalation.

Maximum $T_c$ observed is 5 K with an upper critical field of about 4 T.

Films exhibit reversible electrochromic change from transparent to colored at peak superconductivity.

Abstract

Transparent conductive indium tin oxide (ITO) thin films, electrochemically intercalated with sodium or other cations, show tunable superconducting transitions with a maximum $T_c$ at 5 K. The transition temperature and the density of states, $D(E_F)$ (extracted from the measured Pauli susceptibility $\chi_p$ exhibit the same dome shaped behavior as a function of electron density. Optimally intercalated samples have an upper critical field $\approx 4$ T and $\Delta/{k_BT_c} \approx 2.0$. Accompanying the development of superconductivity, the films show a reversible electrochromic change from transparent to colored and are partially transparent (orange) at the peak of the superconducting dome. This reversible intercalation of alkali and alkali earth ions into thin ITO films opens diverse opportunities for tunable, optically transparent superconductors.