Journal Article

Correlation between the dome-shaped superconducting phase diagram, charge order, and normal-state electronic properties in LaRu 3 Si 2

Luetkens, Hubertus, Wehinger, Björn, Medvedev, Sergey, Nakamura, Hiroto, Guguchia, Zurab, Shin, Soohyeon, Gerguri, Orion, von Rohr, Fabian O, Yin, Jiaxin, Pomjakushina, Ekaterina, Plokhikh, Igor, Nakatsuji, Satoru, Gawryluk, Dariusz J, Graham, Jennifer N, Islam, Shams Sohel, Mielke Iii, Charles, Král, Petr, Sazgari, Vahid, Felser, Claudia, Ma, KeYuan

2025

Overview

The interplay between superconductivity and charge or spin order is a key focus in condensed matter physics, with kagome lattice systems providing unique insights. The kagome superconductor LaRu Si (T  ≃ 6.5 K) features a characteristic kagome band structure and a hierarchy of charge order transitions at T  ≃ 400 K and T  ≃ 80 K, along with an additional transition at T* ≃ 35 K associated with electronic and magnetic responses. Using magnetotransport under pressure up to 40 GPa, we find T peaks at 9 K (2 GPa)-the highest among kagome superconductors-remains nearly constant up to 12 GPa, and then decreases to 2 K at 40 GPa, forming a dome-shaped phase diagram. Similarly, both the resistivity anomaly at T* and the magnetoresistance exhibit a dome-shaped pressure dependence. Moreover, above 12 GPa, X-ray diffraction reveals that the charge order evolves from long-range to short-range, coinciding with the suppression of T . These observations indicate that superconductivity in LaRu Si is closely linked to the charge-ordered state and the electronic responses at T and T*.