paper

Symmetry-enforced minimal entanglement and correlation in quantum spin chains

arXiv:2412.20765 · doi:10.21468/SciPostPhys.19.1.020

Abstract

The interplay between symmetry, entanglement and correlation is an interesting and important topic in quantum many-body physics. Within the framework of matrix product states, in this paper we study the minimal entanglement and correlation enforced by the spin rotation symmetry and lattice translation symmetry in a quantum spin- chain, with a positive integer. When neither symmetry is spontaneously broken, for a sufficiently long segment in a sufficiently large closed chain, we find that the minimal Rényi- entropy compatible with these symmetries is , for any . In an infinitely long open chain with such symmetries, for any the minimal Rényi- entropy of half of the system is . When , these lower bounds give the symmetry-enforced minimal von Neumann entropies in these setups. Moreover, we show that no state in a quantum spin- chain with these symmetries can have a vanishing correlation length. Interestingly, the states with the minimal entanglement may not be a state with the minimal correlation length.

17 pages + appendices + references

References in corpus (37)