Magnetic Properties under Pressure in Novel Spin-Triplet Superconductor UTe2

We report the magnetic susceptibility and the magnetization under pressures up to 1.7 GPa above the critical pressure, P-c similar to 1.5 GPa, for H parallel to a, b, and c-axes in the novel spin triplet superconductor UTe2. The anisotropic magnetic susceptibility at low pressure with the easy magnetization a-axis changes to the quasi-isotropic behavior at high pressure, revealing a rapid suppression of the susceptibility for a-axis, and a gradual increase of the susceptibility for the b-axis. At 1.7 GPa above P-c, magnetic anomalies are detected at T-MO similar to 3K and T-WMO similar to 10 K. The former anomaly corresponds to long-range magnetic order, most likely antiferromagnetism, while the latter shows a broad anomaly, which is probably due to the development of short range order. The unusual decrease and increase of the susceptibility below T-WMO for H parallel to a and b-axes, respectively, indicate the complex magnetic properties at low temperatures above P-c. This is related to the interplay between multiple fluctuations dominated by antiferromagnetism, ferromagnetism, valence and Fermi surface instabilities.

Automated summary

In this study, the magnetic properties of UTe2 under different pressures were investigated, revealing significant changes in magnetic behavior at high pressures, indicating a strong pressure dependence of magnetic properties and complex magnetic interactions.