Contributor info: Prof. Julio Guerrero

Julio Guerrero, Antonio Sojo, Alberto Mayorgas, Manuel Calixto

SciPost Phys. Proc. 14, 029 (2023) · published 24 November 2023 | Toggle abstract · pdf

Along this paper, we analyze the entanglement properties of symmetric multi-quDits systems in a special type of states created from the generalization to U(D) of the usual spin coherent states. By means of parity operators, we define what we call multicomponent Schrödinger cat states as parity adapted coherent states. Introducing the tool of information diagrams, i.e. representations of pairs of entropy measures, we analyze the correlation structure of this type of states and their M-wise reduced density matrices.

Manuel Calixto, Alberto Mayorgas, Julio Guerrero

SciPost Phys. Proc. 14, 021 (2023) · published 23 November 2023 | Toggle abstract · pdf

Using the Lieb–Mattis ordering theorem of electronic energy levels, we identify and construct the Hilbert space of the low energy sector of U(N) quantum Hall/Heisenberg ferromagnets at filling factor M for L Landau/lattice sites. The carrier Hilbert space of irreducible representations of U(N) is described by rectangular Young tableaux of M rows and L columns, and associated with Grassmannian phase spaces U(N)/U(M)×U(N-M). Replacing U(N)-spin operators by their expectation values in a Grassmannian coherent state allows for a semi-classical treatment of the low energy U(N)-spin-wave coherent excitations (skyrmions) of U(N) quantum Hall ferromagnets in terms of Grasmannian nonlinear sigma models.