Possible Phase Transition Deep Inside the Hidden Order Phase of Ultraclean URu2Si2

Shishido, H.; Hashimoto, K.; Shibauchi, T.; Sasaki, T.; Oizumi, H.; Kobayashi, N.; Takamasu, T.; Takehana, K.; Imanaka, Y.; Matsuda, T. D.; Haga, Y.; Onuki, Y.; Matsuda, Y.

Possible Phase Transition Deep Inside the Hidden Order Phase of Ultraclean URu2Si2

Authors

Description

To elucidate the underlying nature of the hidden order (HO) state in heavy-fermion compound URu2Si2, we measure electrical transport properties of ultraclean crystals in a high field/low temperature regime. Unlike previous studies, the present system with much less impurity scattering resolves a distinct anomaly of the Hall resistivity at H*=22.5 T well below the destruction field of the HO phase ~36 T. In addition, a novel quantum oscillation appears above a magnetic field slightly below H*. These results indicate an abrupt reconstruction of the Fermi surface, which implies a possible phase transition well within the HO phase caused by a band-dependent destruction of the HO parameter. The present results definitely indicate that the HO transition should be described by an itinerant electron picture.
4 pages, 4 figures, accepted for publication in Physical Review Letters