Method for Readout of Majorana Parity in Topological Superconductors Using Magnetic Force Microscopy*

Recently, FeTe_xSe_1-x has been shown to host Majorana zero-energy modes (MZMs) in topological superconducting vortex cores. Pairs of MZMs can potentially be used as topologically protected qubits. By applying a surface Fu-Kane model, we numerically calculate the wavefunction solution to the Bogoliubov-de Gennes equation for both a pair of spatially separated single vortices and the double vortex limit of complete overlap. We then compute the supercurrent generated by zero-energy mode splitting and the resulting magnetic field gradient above the surface. We conclude it is possible to measure the presence of this excess supercurrent, and thus the quantum state of the MZM pair, using magnetic force microscopy[1].

[1] B. H. November, J. D. Sau, J. R. Williams, and J. E. Hoffman, “Scheme for Majorana Manipulation Using Magnetic Force Microscopy,” arXiv:1905.09792.