Robust multipartite entanglement in dirty topological wires

TL;DR

This paper investigates multipartite entanglement in disordered topological wires, revealing robustness of entanglement scaling as a key indicator of topological phases despite spatial disorder.

Contribution

It extends the analysis of multipartite entanglement to generalized Kitaev chains with disorder and long-range pairing, highlighting its robustness and phase diagram complexity.

Findings

Heisenberg scaling of QFI indicates topological phases with Majorana modes.

Long-range pairing leads to super-extensive QFI, identifying long-range phases.

Multipartite entanglement remains robust against spatial inhomogeneity.

Abstract

Identifying and characterizing quantum phases of matter in the presence of long range correlations and/or spatial disorder is, generally, a challenging and relevant task. Here, we study a generalization of the Kiteav chain with variable-range pairing and different site-dependence of the chemical potential, addressing commensurable and incommensurable modulations as well as Anderson disorder. In particular, we analyze multipartite entanglement (ME) in the ground state of the dirty topological wires by studying the scaling of the quantum Fisher information (QFI) with the system's size. For nearest-neighbour pairing the Heisenberg scaling of the QFI is found in one-to-one correspondence with topological phases hosting Majorana modes. For finite-range pairing, we recognize long-range phases by the super-extensive scaling of the QFI and characterize complex lobe-structured phase diagrams. Overall, we observe that ME is robust against finite strengths of spatial inhomogeneity. This work contributes to establish ME as a central quantity to study intriguing aspects of topological systems.