Die u:cris Detailansicht:

Elementary Excitations in Gapped Quantum Spin Systems

Autor(en)
Jutho Haegeman, Spyridon Michalakis, Bruno Nachtergaele, Tobias J. Osborne, Norbert Schuch, Frank Verstraete
Abstrakt

For quantum lattice systems with local interactions, the Lieb-Robinson bound serves as an alternative for the strict causality of relativistic systems and allows the proof of many interesting results, in particular, when the energy spectrum exhibits an energy gap. In this Letter, we show that for translation invariant systems, simultaneous eigenstates of energy and momentum with an eigenvalue that is separated from the rest of the spectrum in that momentum sector can be arbitrarily well approximated by building a momentum superposition of a local operator acting on the ground state. The error satisfies an exponential bound in the size of the support of the local operator, with a rate determined by the gap below and above the targeted eigenvalue. We show this explicitly for the Affleck-Kennedy-Lieb-Tasaki model and discuss generalizations and applications of our result.

Organisation(en)
Quantenoptik, Quantennanophysik und Quanteninformation
Externe Organisation(en)
Ghent University , California Institute of Technology (Caltech), University of California, Davis, Gottfried Wilhelm Leibniz Universität Hannover, Rheinisch-Westfälische Technische Hochschule Aachen
Journal
Physical Review Letters
Band
111
Anzahl der Seiten
5
ISSN
0031-9007
DOI
https://doi.org/10.1103/PhysRevLett.111.080401
Publikationsdatum
08-2013
Peer-reviewed
Ja
ÖFOS 2012
103036 Theoretische Physik, 103026 Quantenoptik
Schlagwörter
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/7e27c1c0-069b-42e0-bc04-2c4bb3588180