Direct observation of lattice symmetry breaking at the hidden-order transition in URu 2 Si 2

S. Tonegawa, S. Kasahara, T. Fukuda, K. Sugimoto, N. Yasuda, Y. Tsuruhara, D. Watanabe, Y. Mizukami, Y. Haga, T. D. Matsuda, E. Yamamoto, Y. Onuki, H. Ikeda, Y. Matsuda, T. Shibauchi

Research output: Contribution to journalArticlepeer-review

50 Citations (Scopus)

Abstract

Since the 1985 discovery of the phase transition at T HO =17.5 K in the heavy-fermion metal URu 2 Si 2, neither symmetry change in the crystal structure nor large magnetic moment that can account for the entropy change has been observed, which makes this hidden order enigmatic. Recent high-field experiments have suggested electronic nematicity that breaks fourfold rotational symmetry, but direct evidence has been lacking for its ground state in the absence of magnetic field. Here we report on the observation of lattice symmetry breaking from the fourfold tetragonal to twofold orthorhombic structure by high-resolution synchrotron X-ray diffraction measurements at zero field, which pins down the space symmetry of the order. Small orthorhombic symmetry-breaking distortion sets in at T HO with a jump, uncovering the weakly first-order nature of the hidden-order transition. This distortion is observed only in ultrapure samples, implying a highly unusual coupling nature between the electronic nematicity and underlying lattice.

Original languageEnglish
Article number4188
JournalNature communications
Volume5
DOIs
Publication statusPublished - Jun 19 2014
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

Fingerprint

Dive into the research topics of 'Direct observation of lattice symmetry breaking at the hidden-order transition in URu 2 Si 2'. Together they form a unique fingerprint.

Cite this