Quantifying robustness and locality of Majorana bound states in interacting systems
arXiv:2510.20538 · doi:10.1103/pw51-tnsz
Abstract
Protecting qubits from perturbations is a central challenge in quantum computing. Topological superconductors with separated Majorana bound states (MBSs) provide a strong form of protection that only depends on the locality of perturbations. While the link between MBS separation, robust degeneracy, and protected braiding is well understood in non-interacting systems, recent experimental progress in short quantum-dot-based Kitaev chains highlights the need to establish these connections rigorously for interacting systems. We do this by defining MBSs from many-body ground states and show how their locality constrains their coupling to an environment. This, in turn, quantifies the protection of the energy degeneracy and the feasibility of non-abelian braiding.
21 pages, 7 figures. v2: Expanded examples (Sec. VI.C and Sec. VII new). Matches publication