English

Superconducting Dome in Ionic Liquid Gated Homoepitaxial Strontium Titanate Thin Films

Superconductivity 2026-03-31 v3 Mesoscale and Nanoscale Physics

Abstract

In this work, we patterned a two-dimensional electron gas (2DEG) on the surface of a SrTiO3_3 thin film grown homoepitaxially on SrTiO3_3 by hybrid molecular beam epitaxy (hMBE). We explored the superconducting dome in this material system by tuning electron density with ionic liquid gating. We found superconducting transitions up to 503 mK near an optimal electron density of approximately 3 ×\times 1013^{13} cm2^{-2}. This is a meaningful increase from the typical optimal transition near 350 mK in similar 2DEGs on SrTiO3_3 single crystal substrate surfaces. Systematic tuning of 2DEG electron density revealed a consistent BCS scaling between superconducting critical temperature, coherence length, and electron mean free path. Substantial variation of transition width across the dome was described by a paraconductivity model combining Aslamazov-Larkin and Maki-Thompson contributions.

Keywords

Cite

@article{arxiv.2509.16408,
  title  = {Superconducting Dome in Ionic Liquid Gated Homoepitaxial Strontium Titanate Thin Films},
  author = {Sushant Padhye and Jin Yue and Shivasheesh Varshney and Bharat Jalan and David Goldhaber-Gordon and Evgeny Mikheev},
  journal= {arXiv preprint arXiv:2509.16408},
  year   = {2026}
}