Unwithered Majorana fermions in the bulk of a quantum chain

The proposal is to probe Majorana modes in the system when its parameters are tuned to bring it into a disentangled ground state, which occur on the parametric curves known as disorder lines (DL). In such state certain correlation functions do not depend on separation. The exact results are presented for the XY spin chain in transverse field, also called the Kitaev chain in the Majorana representation. The single Majorana modes are shown to be localized near the ends of the chain, as in the states off the DL, while the disentangled $n$-particle Majorana modes ($n \geq 2$) penetrate into the bulk without attenuation. The predicted bulk-edge effects can be detected in the specially engineered optical chains and lattices.

Source: arXiv:2607.29615v1 - http://arxiv.org/abs/2607.29615v1 PDF: https://arxiv.org/pdf/2607.29615v1 Original Link: http://arxiv.org/abs/2607.29615v1