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  • Open Access

Entanglement spectrum of gapless topological phases: A case study with topological superconductors

Archi Banerjee1,2,3 and Meng Zeng1,*

  • *Contact author: mengzeng@pks.mpg.de
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Phys. Rev. B 114, 055104 – Published 6 July, 2026

DOI: https://doi.org/10.1103/svtx-7m6q

Abstract

Using bulk gapless topological superconductors in both 1D and 2D as free fermion model examples, we demonstrate the power of subsystem correlation spectrum (the spectrum of correlation matrix), or equivalently the entanglement spectrum for the case of free fermions, in characterizing the topology of the nontrivial ground state. For the systems considered, we show that signatures of the low-energy spectrum, including both the edge modes and the bulk modes, appear in the correlation spectrum, albeit with different behaviors. This work generalizes the 2D Li-Haldane entanglement spectrum characterization of topological edge states to 2D topological systems with gapless bulk.

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Phys. Rev. B 114, 055104– Published 6 July, 2026
  • Received 18 October 2025
  • Revised 18 June 2026
  • Accepted 22 June 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by Max Planck Society.

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