DQMP Seminar - Two-dimensional superconductivity at KTaO3 interfaces

02.02.2021 13:00 – 14:30

Two-dimensional superconductivity at KTaO3 interfaces

The unique electronic structure found at interfaces between materials can allow unconventional quantum states to emerge. One prominent example is the emergence of a superconducting electron gas at the interface of LaAlO3/SrTiO3. I will talk about our recent work on the observation of superconductivity in electron gases formed at interfaces between (111) oriented KTaO3 and insulating overlayers of either EuO or LaAlO3. The superconducting transition temperature Tc, reaching 2.2 K, is about one order of magnitude higher than that of the LaAlO3/SrTiO3 system. This superconductivity shows strong crystallographic orientation dependence. Electron gases form in the KTaO3 (001) surface with similar carrier densities remain normal down to 25 mK. The critical field and IV measurements indicate that the superconductivity is two dimensional. Low-carrier density EuO/KTaO3(111) samples, with higher mobility, show spontaneous in-plane transport anisotropy at temperatures prior to the onset of global superconductivity, suggesting the emergence of a stripe phase where the superconductivity is nearly homogeneous in one direction, but modulated in the other.

Reference: https://doi.org/10.1126/science.aba5511

Organisé par : Prof. Dirk van der Marel

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Zoom meeting

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