Discovery of two-dimensional anisotropic superconductivity at KTaO<sub>3</sub> (111) interfaces
ORAL
Abstract
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. Here we observe superconductivity in electron gases formed at interfaces between (111) oriented KTaO3 and insulating overlayers of either EuO or LaAlO3. The superconducting transition temperature, approaching 2.2 K, is about one order of magnitude higher than that of the LaAlO3/SrTiO3 system. Strikingly, similar electron gases at (001) KTaO3 interfaces 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 mobilities, show spontaneous in-plane transport anisotropy at temperatues 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: C. Liu et al., arXiv:2004.07416
Reference: C. Liu et al., arXiv:2004.07416
*Supported by the US DOE, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The use of facilities at the CNM was supported by the DOE, Basic Energy Sciences under Contract No. DE-AC02-06CH11357.
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Presenters
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Changjiang Liu
- Argonne National Laboratory
- Materials Science Division, Argonne National Laboratory