Topological nematic phase transition in Kitaev magnets under applied magnetic fields

We propose a scenario of realizing the toric code phase, which can be potentially utilized for fault-tolerant quantum computation, in candidate materials of Kitaev magnets. It is demonstrated that four-body interactions among Majorana fermions in the Kitaev spin liquid state, which are induced by applied magnetic fields as well as non-Kitaev-type exchange interactions, trigger a nematic phase transition of Majorana bonds without magnetic orders, accompanying the change of the Chern number from +/- 1 to zero. This gapful spin liquid state with zero Chern number is simply the toric code phase. Our result potentially explains the topological nematic transition recently observed in alpha-RuCl3 via heat capacity measurements (O. Tanaka et al., arXiv:2007.06757).

Automated summary

Researchers propose a scenario for realizing the toric code phase in candidate materials of Kitaev magnets, which could potentially be used for fault-tolerant quantum computation. The study demonstrates that four-body interactions among Majorana fermions in the Kitaev spin liquid state can induce a nematic phase transition of Majorana bonds, leading to a gapful spin liquid state with zero Chern number, known as the toric code phase. This potentially explains the topological nematic transition observed in alpha-RuCl3 recently.