2025/08/29 by Jaden Thomas-Markarian, Kartiek Agarwal, Thomas-Markarian, Jaden +3 · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Boundary (topology) #Fermion #MAJORANA #Majorana equation #Majorana fermion #Quasiparticle #Rare-earth and actinide compounds #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.2509.00158
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2025/08/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Topological superconductors are believed to host exotic quasiparticle excitations known as Majorana zero-modes (MZMs), with much of the evidence based on BCS mean-field theory. The direct application of mean-field arguments is tenuous in finite, isolated systems relevant in some experiments. Here, we develop a new correlation-based method for identifying MZMs in interacting, number-conserving systems. Using DMRG, we study fermion number-conserving models with long-range interactions, which under periodic boundary conditions exhibit robust topological and non-topological superconductivity, tuned by the strength of interaction [1]. We find evidence that, on the topological side, Majorana edge modes appear in open chains, manifesting as the vanishing of the energy splitting between odd- and even-parity ground states with increasing system size. Additionally, off-diagonal two-point correlation functions show nonlocal, parity-dependent edge effects. These correlations reveal the spatial structure of Majorana modes in the many-body wavefunction. We show that the correlation diagnostic applies broadly, including to short-range interacting models, where topological superconductivity is more fragile due to the absence of a bulk excitation gap.