Fock-space geometry and strong correlations in many-body localized systems

Christian P. Chen; Henning Schomerus

doi:10.1103/physrevb.104.205411

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arXiv · 2107.05502

Fock-space geometry and strong correlations in many-body localized systems

Christian P. Chen·Henning Schomerus

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Abstract

We adopt a geometric perspective on Fock space to provide two complementary insights into the eigenstates in many-body-localized fermionic systems. On the one hand, individual many-bodylocalized eigenstates are well approximated by a Slater determinant of single-particle orbitals. On the other hand, the orbitals of different eigenstates in a given system display a varying, and generally imperfect, degree of compatibility, as we quantify by a measure based on the projectors onto the corresponding single-particle subspaces. We study this incompatibility between states of fixed and differing particle number, as well as inside and outside the many-body-localized regime. This gives detailed insights into the emergence and strongly correlated nature of quasiparticle-like excitations in many-body localized systems, revealing intricate correlations between states of different particle number down to the level of individual realizations.

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Christian P. Chen, Henning Schomerus. 2021-10-13. Fock-space geometry and strong correlations in many-body localized systems. https://doi.org/10.1103/physrevb.104.205411

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