Correlated States in \(\beta\)-\(\rm{Li}\)\(_2\)\(\rm{IrO}\)\(_3\) Driven by Applied Magnetic Fields

Alejandro Ruiz, Alex Frano, Nicholas P. Breznay, Itamar Kimchi, Toni Helm, Iain Oswald, Julia Y. Chan, R. J. Birgeneau, Zahirul Islam, and James G. Analytis

Nature Communications 8 (2017) 961

Abstract

Magnetic honeycomb iridates are thought to show strongly spin-anisotropic exchange interactions which, when highly frustrated, lead to an exotic state of matter known as the Kitaev quantum spin liquid. However, in all known examples these materials magnetically order at finite temperatures, the scale of which may imply weak frustration. Here we show that the application of a relatively small magnetic field drives the three-dimensional magnet \(\beta\)-\(\rm{Li}\)\(_2\)\(\rm{IrO}\)\(_3\) from its incommensurate ground state into a quantum correlated paramagnet. Interestingly, this paramagnetic state admixes a zig-zag spin mode analogous to the zig-zag order seen in other Mott-Kitaev compounds. The rapid onset of the field-induced correlated state implies the exchange interactions are delicately balanced, leading to strong frustration and a near degeneracy of different ground states.