Research: Field-induced quantum paramagnet and quantum criticality in alpha-RuCl3

The material alpha-RuCl₃ is a prime candidate for realizing so-called compass interactions among local-moments on the honeycomb lattice, which by themselves are known to stabilize a fractionalized spin-liquid phase due to Kitaev, with emergent Majorana-fermion excitations. Our thermodynamic and NMR experiments show that magnetic order, present in alpha-RuCl₃ under ambient conditions, is suppressed by a moderate magnetic field of order 10 T, giving way to a quantum paramagnetic phase. The loss of order is accompanied by quantum critical behavior, and the phase emerging at elevated phase is a candidate for a field-induced spin liquid.

S.-H. Baek, S.-H. Do, K.-Y. Choi, Y. S. Kwon, A. U. B. Wolter, S. Nishimoto, J. van den Brink, B. Büchner,
Evidence for a Field-Induced Quantum Spin Liquid in alpha-RuCl₃,
Phys. Rev. Lett. 119, 037201 (2017) (arXiv)

A. U. B. Wolter, L. T. Corredor, L. Janssen, K. Nenkov, S. Schönecker, S.-H. Do, K.-Y. Choi, R. Albrecht, J. Hunger, T. Doert, M. Vojta, B. Büchner,
Field-induced quantum criticality in the Kitaev system alpha-RuCl₃,
Phys. Rev. B 96, 041405(R) (2017) (arXiv)