Presentation Information
[3F17]Detecting signatures of Majorana quasiparticle at vortex cores of Fe(Se,Te)
*Tadashi Machida1 (1. RIKEN CEMS)
Vortex cores of topological superconductors are predicted to be an ideal platform for Majorana fermions. Although several experimental efforts have been made to detect Majorana fermions in the vortex cores as a zero-energy vortex bound state (ZVBS), the existence of the Majorana fermions is still controversial. Using a dilution-refrigerator scanning tunneling microscope [5], we have systematically examined a large number of vortices in the superconducting topological surface state of FeTe0.6Se0.4 with unprecedentedly high energy resolution of ~20 meV. We found that a certain number of vortices possess the ZVBS below 20 meV, which suggests its Majorana bound-state origin. However, we also found vortices without the ZVBS. Interestingly, the fraction of vortices with the ZVBS decreases with increasing magnetic field. These findings suggest that inter-Majorana interaction plays an important role in the ZVBS formation