Anomalous Normal Fluid Response in Chiral Superconductor UTe2

Published

May 10, 2021

Author(s)

Seokjin Bae, Hyunsoo Kim, Yun S. Eo, Nicholas Butch, Sheng Ran

Abstract

A chiral superconductor has been proposed as one pathway to realize topological quantum computation utilizing the predicted Majorana normal fluid at its boundary1^1-4 (i.e., a point, edge, or surface). The search for experimental realizations has led to the discovery of 1D⁵ and 2D⁶ chiral superconducting systems. However, the long-sought 3D chiral superconductor with surface Majorana normal fluid is yet to be found. Here we report evidence for a chiral spin-triplet pairing state of UTe₂ with significant surface normal fluid response. The microwave surface impedance of UTe₂ crystals was measured and converted to complex conductivity. The anomalous residual normal fluid conductivity in the zero temperature limit supports the presence of a significant normal fluid response. The super fluid conductivity follows the low temperature behavior predicted for the chiral spin-triplet state. The temperature dependence of the super fluid conductivity also reveals a low impurity scattering rate and low frequency-to-energy-gap ratio, implying that the observed normal fluid response does not have a trivial origin. Our findings suggest that UTe₂ can be a new platform to study exotic topological excitations in higher dimension, and may play the role of a versatile 3D building block in the future era of topological quantum computation.

Citation

Nature Communications

Volume

12

Issue

1

Pub Type

Journals

Download Paper

DOI Link

Keywords

superconductor, microwave, penetration depth

Citation

Bae, S. , Kim, H. , Eo, Y. , Butch, N. and Ran, S. (2021), Anomalous Normal Fluid Response in Chiral Superconductor UTe₂, Nature Communications, [online], https://doi.org/10.1038/s41467-021-22906-6 (Accessed April 25, 2024)