MaxEnt principle and reduced density matrix estimation

MARCELO LOSADA; VICTOR PENAS; F. HOLIK; P.W. LAMBERTI

PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2022 vol. 600 p. 1 - 9

0378-4371

n this work we study the reduced density matrices of sublattices of fermionic, bosonicand spin lattice models. Firstly, we consider fermionic and bosonic lattice models,and we show that the reduced density matrix associated with a sublattice coincideswith the state obtained by applying the maximum entropy principle under suitablychosen constraints. Secondly, for informationally incomplete scenarios, we consideredspin lattice models. We study the performance of the MaxEnt method for estimating thereduced density matrix of sublattices of the lattice system. We find that the performanceof the MaxEnt estimation improves not only with the number of measured observables(as expected), but also with the lattice length. In these cases, the MaxEnt solution canbe considered, not as an exact solution, but as a good estimaton.