Uniaxial spin texture in a superconducting electron gas revealed by exchange interactions

Junyi Yang; Changjiang Liu; Xianjing Zhou; Hanyu Hou; Kaijun Yin; Jianguo Wen; John Pearson; Alexey Suslov; Dafei Jin; Jidong S Jiang; Ulrich Welp; Jian-Min Zuo; Michael R Norman; Anand Bhattacharya

doi:10.1126/sciadv.aeb1601

Uniaxial spin texture in a superconducting electron gas revealed by exchange interactions

Sci Adv. 2026 May 8;12(19):eaeb1601. doi: 10.1126/sciadv.aeb1601. Epub 2026 May 8.

Authors

Junyi Yang¹, Changjiang Liu^{1

2}, Xianjing Zhou^{3

4

5}, Hanyu Hou⁶, Kaijun Yin⁶, Jianguo Wen³, John Pearson^{1

3}, Alexey Suslov⁴, Dafei Jin^{3

7}, Jidong S Jiang¹, Ulrich Welp¹, Jian-Min Zuo⁶, Michael R Norman¹, Anand Bhattacharya¹

Affiliations

¹ Materials Science Division, Argonne National Laboratory, Lemont, IL, USA.
² Department of Physics, University at Buffalo, SUNY, Buffalo, NY, USA.
³ Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, USA.
⁴ National High Field Magnetic Laboratory, Tallahassee, FL, USA.
⁵ Florida State University, Tallahassee, FL, USA.
⁶ Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
⁷ University of Notre Dame, Notre Dame, IN, USA.

Abstract

Two-dimensional (2D) superconductors with spin-textured Fermi surfaces can be a platform for realizing unconventional pairing states and are of substantial interest in the context of quantum information science and superconducting spintronics/orbitronics. We observed an unusual in-plane uniaxial anisotropy in the superconducting 2D electron gas (2DEG) formed at EuO_x/KTaO₃ (110) interfaces. This anisotropy is not evident in AlO_x/KTaO₃ (110) where the overlayer is nonmagnetic. Our results are consistent with a highly anisotropic "half-Rashba" spin-textured Fermi surface in 2DEGs formed at the KTaO₃ (110) interface that is hidden from external magnetic fields due to a near cancellation between orbital and spin moments but revealed by exchange interactions of the electrons in the 2DEG with Eu moments near the EuO_x/KTaO₃ (110) interface. The interactions between the uniaxial spin texture and the magnetic overlayer offer previously unexplored ways to explore the interplay between magnetism and 2D superconductivity.