Emergent Antiferromagnetism out of the ``Hidden-Order'' State in ${\mathrm{URu}}_{2}{\mathrm{Si}}_{2}$: High Magnetic Field Nuclear Magnetic Resonance to 40 T

Emergent Antiferromagnetism out of the “Hidden-Order” State in ${URu}_{2} {Si}_{2}$ : High Magnetic Field Nuclear Magnetic Resonance to 40 T

H. Sakai, Y. Tokunaga, S. Kambe, R. R. Urbano, M.-T. Suzuki, P. L. Kuhns, A. P. Reyes, P. H. Tobash, F. Ronning, E. D. Bauer, and J. D. Thompson

Phys. Rev. Lett. 112, 236401 – Published 10 June 2014

Abstract

Very high field ${}^{29}{Si}$ -NMR measurements using a fully ${}^{29}{Si}$ -enriched ${URu}_{2} {Si}_{2}$ single crystal were carried out in order to microscopically investigate the “hidden order” (HO) state and adjacent magnetic phases in the high field limit. At the lowest measured temperature of 0.4 K, a clear anomaly reflecting a Fermi surface instability near 22 T inside the HO state is detected by the ${}^{29}{Si}$ shift, ${}^{29}{K_{c}}$ . Moreover, a strong enhancement of ${}^{29}{K_{c}}$ develops near a critical field $H_{c} ≃ 35.6 T$ , and the ${}^{29}{Si}$ -NMR signal disappears suddenly at $H_{c}$ , indicating the total suppression of the HO state. Nevertheless, a weak and shifted ${}^{29}{Si}$ -NMR signal reappears for fields higher than $H_{c}$ at 4.2 K, providing evidence for a magnetic structure within the magnetic phase caused by the Ising-type anisotropy of the uranium ordered moments.

Received 18 December 2013

DOI:https://doi.org/10.1103/PhysRevLett.112.236401

Authors & Affiliations

H. Sakai^*, Y. Tokunaga, and S. Kambe

Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan

R. R. Urbano

Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, 13083-859 Campinas, SP, Brazil and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA

M.-T. Suzuki^†