Unpaired Majorana modes in the gapped phase of Kitaev's honeycomb model

Olga Petrova, Paula Mellado, Oleg Tchernyshyov
2013 Physical Review B  
We study the gapped phase of Kitaev's honeycomb model (a Z_2 spin liquid) in the presence of lattice defects. We find that some dislocations and bond defects carry unpaired Majorana fermions. Physical excitations associated with these defects are (complex) fermion modes made out of two (real) Majorana fermions connected by a Z_2 gauge string. The quantum state of these modes is robust against local noise and can be changed by winding a Z_2 vortex around a dislocation. The exact solution
more » ... gauge invariance and reveals a crucial role of the gauge field in the physics of Majorana modes.
doi:10.1103/physrevb.88.140405 fatcat:iz73tniu4nfw5iyvtjiz3k5cbm