Cat states carrying long-range correlations

in the many-body localized phase

PRB 112, 224207 (2025)

See also : JC, FA & NL, PRB 110, 214210 (2024)

Nicolas Laflorencie, Jeanne Colbois and Fabien Alet

LPT Toulouse (Univ. Toulouse & CNRS) & Institut Néel (UGA, Grenoble INP & CNRS)

1. We study rare events with large correlations at maximal distance in the many-body spectrum of the random-field XXZ chain

2. These arise in pairs, revealing a broad region deep into the MBL regime where long-range cat-like states occur

3. An analytical description gives the main observables supporting a detailed characterization.