2023 journal article
Anisotropic superconductivity at KTaO 3 (111) interfaces
Science Advances.
doi.org (publisher)
Source: ORCID
Added: February 16, 2023
A two-dimensional, anisotropic superconductivity was recently found at the KTaO 3 (111) interfaces. The nature of the anisotropic superconducting transition remains a subject of debate. To investigate the origins of the observed behavior, we grew epitaxial KTaO 3 (111)-based heterostructures. We show that the superconductivity is robust against the in-plane magnetic field and violates the Pauli limit. We also show that the Cooper pairs are more resilient when the bias is along [11 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>2</mml:mn> <mml:mo accent="false">¯</mml:mo> </mml:mover> </mml:math> ] (I ∥ [11 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>2</mml:mn> <mml:mo accent="false">¯</mml:mo> </mml:mover> </mml:math> ]) and the magnetic field is along [1 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>1</mml:mn> <mml:mo accent="false">¯</mml:mo> </mml:mover> </mml:math> 0] ( B ∥ [1 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>1</mml:mn> <mml:mo accent="false">¯</mml:mo> </mml:mover> </mml:math> 0]). We discuss the anisotropic nature of superconductivity in the context of electronic structure, orbital character, and spin texture at the KTaO 3 (111) interfaces. The results point to future opportunities to enhance superconducting transition temperatures and critical fields in crystalline, two-dimensional superconductors with strong spin-orbit coupling.
