What causes the variation in superconducting properties of UTe$_{2}$?

Fuente: arXiv
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Main Authors: Kengle, C. S., Schnitzer, Noah, Bordelon, M. M., Thomas, S. M., Rosa, P. F. S.
Format: Preprint
Published: 2025
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author Kengle, C. S.
Schnitzer, Noah
Bordelon, M. M.
Thomas, S. M.
Rosa, P. F. S.
author_facet Kengle, C. S.
Schnitzer, Noah
Bordelon, M. M.
Thomas, S. M.
Rosa, P. F. S.
contents Reaching a consensus on the superconducting order parameter of unconventional superconductors remains a central challenge in the field of magnetically-mediated superconductivity. Though UTe$_{2}$ is largely accepted as a rare example of an odd-parity superconductor, its precise order parameter remains highly debated, even at ambient conditions. A key underlying issue is the large sample-to-sample variation in superconducting properties at zero applied pressure and magnetic field. Here, we investigate the origin of the observed variation by means of single crystal x-ray diffraction (SC-XRD) and scanning transmission electron microscopy (STEM) measurements. Our results reveal highly ordered crystalline lattices, in agreement with the expected $Immm$ structure, and no signs of uranium vacancies. Tiny amounts of interstitial defects, however, are observed on the Te2 layers that host Te chains along the b axis. We argue that these defects give rise to slightly enhanced atomic displacement parameters observed in SC-XRD data and are enough to disrupt the unconventional superconducting state in UTe$_{2}$. Our findings highlight the need to focus future order parameter determination efforts on single crystals of UTe$_{2}$ with minimal amounts of structural disorder.
format Preprint
id arxiv_https___arxiv_org_abs_2509_20298
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle What causes the variation in superconducting properties of UTe$_{2}$?
Kengle, C. S.
Schnitzer, Noah
Bordelon, M. M.
Thomas, S. M.
Rosa, P. F. S.
Superconductivity
Strongly Correlated Electrons
Reaching a consensus on the superconducting order parameter of unconventional superconductors remains a central challenge in the field of magnetically-mediated superconductivity. Though UTe$_{2}$ is largely accepted as a rare example of an odd-parity superconductor, its precise order parameter remains highly debated, even at ambient conditions. A key underlying issue is the large sample-to-sample variation in superconducting properties at zero applied pressure and magnetic field. Here, we investigate the origin of the observed variation by means of single crystal x-ray diffraction (SC-XRD) and scanning transmission electron microscopy (STEM) measurements. Our results reveal highly ordered crystalline lattices, in agreement with the expected $Immm$ structure, and no signs of uranium vacancies. Tiny amounts of interstitial defects, however, are observed on the Te2 layers that host Te chains along the b axis. We argue that these defects give rise to slightly enhanced atomic displacement parameters observed in SC-XRD data and are enough to disrupt the unconventional superconducting state in UTe$_{2}$. Our findings highlight the need to focus future order parameter determination efforts on single crystals of UTe$_{2}$ with minimal amounts of structural disorder.
title What causes the variation in superconducting properties of UTe$_{2}$?
topic Superconductivity
Strongly Correlated Electrons
url https://arxiv.org/abs/2509.20298