The recent discovery of superconducting interfaces in the KTaO3(111)-based heterostructures is intriguing, since a much higher superconducting critical temperature (TC ~ 2 K) is achieved compared to that in the SrTiO3 heterostructures (~ 300 mK). In this paper, we report the superconducting properties of EuO/KTaO3(111) interface as a function of the interface carrier density (ns). The maximum T_C is observed to be ~ 2 K at ns ~ 1×1014 cm-2. In addition, we show that the critical current density and the upper critical magnetic field can be effectively tuned by the back gate voltage. Interestingly, the gate dependence of the upper critical magnetic field exhibits a trend opposite to that of TC in the underdoped region, suggesting a relatively larger Cooper pairing potential.
@article{arxiv.2111.06081,
title = {Gate-tunability of the superconducting state at the $EuO/KTaO_3 (111)$ interface},
author = {Weiliang Qiao and Yang Ma and Jiaojie Yan and Wenyu Xing and Yunyan Yao and Ranran Cai and Boning Li and Richen Xiong and X. C. Xie and Xi Lin and Wei Han},
journal= {arXiv preprint arXiv:2111.06081},
year = {2021}
}