Thermodynamic signatures of short-range magnetic correlations in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi mathvariant="normal">UTe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>
Kristin Willa, F. Hardy, Dai Aoki, Dexin Li, P. Wiecki, G. Lapertot, C. Meingast
Abstract
The normal state out of which unconventional superconductivity in ${\mathrm{UTe}}_{2}$ emerges is studied in detail using a variety of thermodynamic and transport probes. Clear evidence for a broad Schottky-like anomaly with roughly $R\phantom{\rule{0.16em}{0ex}}\text{ln}2$ entropy around ${T}^{*}\ensuremath{\approx}12$ K is observed in all measured quantities. Comparison with high magnetic field transport data allows the construction of an $H\text{\ensuremath{-}}T$ phase diagram resembling that of the ferromagnetic superconductor URhGe. The low-field electronic Gr\"uneisen parameter of ${T}^{*}$ and that of the metamagnetic transition at ${H}_{m}\ensuremath{\approx}35$ T are comparable pointing to a common origin of both phenomena. Enhanced Wilson and Korringa ratios suggest that the existence of short-range ferromagnetic fluctuations cannot be ruled out.