Detuning the Honeycomb of $\alpha$-RuCl${}_3$: Pressure-Dependent Optical Studies Reveal Broken Symmetry

Tobias Biesner, Sananda Biswas, Weiwu Li +10

The honeycomb Mott insulator $\alpha$-RuCl${}_3$ loses its low-temperature magnetic order by pressure. We report clear evidence for a dimerized structure at $P>1$ GPa and observe the brea…