Scattering particles in quantum spin chains

Autor(en)

Laurens Vanderstraeten, Frank Verstraete, Jutho Haegeman

Abstrakt

A variational approach for constructing an effective particle description of the low-energy physics of one-dimensional quantum spin chains is presented. Based on the matrix product state formalism, we compute the one- and two-particle excitations as eigenstates of the full microscopic Hamiltonian. We interpret the excitations as particles on a strongly correlated background with nontrivial dispersion relations, spectral weights, and two-particle S matrices. Based on this information, we show how to describe a finite density of excitations as an interacting gas of bosons, using its approximate integrability at low densities. We apply our framework to the Heisenberg antiferromagnetic ladder: we compute the elementary excitation spectrum and the magnon-magnon S matrix, study the formation of bound states, and determine both static and dynamic properties of the magnetized ladder.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Ghent University

Journal

Physical Review B

Band

92

Anzahl der Seiten

38

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.92.125136

Publikationsdatum

09-2015

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103015 Kondensierte Materie

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/6997ff67-d3d2-4ede-9d64-c8dcb5166bb2