Gapless Spin Excitations in the Field-Induced Quantum Spin Liquid Phase of α-RuCl_{3}

Jiacheng Zheng; Kejing Ran; Tianrun Li; Jinghui Wang; Pengshuai Wang; Bin Liu; Zheng-Xin Liu; B Normand; Jinsheng Wen; Weiqiang Yu

doi:10.1103/PhysRevLett.119.227208

Gapless Spin Excitations in the Field-Induced Quantum Spin Liquid Phase of α-RuCl_{3}

Phys Rev Lett. 2017 Dec 1;119(22):227208. doi: 10.1103/PhysRevLett.119.227208. Epub 2017 Dec 1.

Authors

Jiacheng Zheng^{1

2}, Kejing Ran³, Tianrun Li¹, Jinghui Wang³, Pengshuai Wang¹, Bin Liu², Zheng-Xin Liu¹, B Normand⁴, Jinsheng Wen^{3

5}, Weiqiang Yu^{1

6}

Affiliations

¹ Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China.
² Department of Physics, Beijing Jiaotong University, Beijing 100044, China.
³ National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.
⁴ Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland.
⁵ Innovative Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China.
⁶ Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.

PMID: 29286810
DOI: 10.1103/PhysRevLett.119.227208

Abstract

α-RuCl_{3} is a leading candidate material for the observation of physics related to the Kitaev quantum spin liquid (QSL). By combined susceptibility, specific-heat, and nuclear-magnetic-resonance measurements, we demonstrate that α-RuCl_{3} undergoes a quantum phase transition to a QSL in a magnetic field of 7.5 T applied in the ab plane. We show further that this high-field QSL phase has gapless spin excitations over a field range up to 16 T. This highly unconventional result, unknown in either Heisenberg or Kitaev magnets, offers insight essential to establishing the physics of α-RuCl_{3}.