Identification of isolated Majorana zero modes (MZMs) is a key step toward the realization of fault-tolerant topological quantum computation. Here we show how the $T_1$-based noise magnetometry of a nitrogen-vacancy (NV) center qubit can reveal unique signatures of Majorana fermions bound to vacancies in a non-Abelian Kitaev quantum spin liquid (KQSL). The $1/T_1$ of the NV center is found to increase significantly when the working frequency of the NV center matches the energy difference between a MZM and a low-energy hybridized mode involving dangling Majorana fermions adjacent to vacancies. In experiments, this energy difference can be tuned by an external Zeeman field. Owing to the large excitation gap for flipping a local $Z_2$ gauge field, compared to the working frequency of NV centers, the $1/T_1$ spectrum is robust against other fluctuations in KQSLs at low temperatures. Our study presents a promising probe for identifying the non-Abelian phase in Kitaev materials.

Close

PrevNext

View figure in article

• Fractionalization
• Majorana fermions
• NV centers
• Quantum spin liquid
• Two-dimensional electron system
• Kitaev model