Low-energy behavior of strongly interacting bosons on a flat-band lattice above the critical filling factor

Phillips, Lawrence G.; De Chiara, Gabriele; Ohberg, Patrik; Valiente Cifuentes, Manuel

Publication:
Low-energy behavior of strongly interacting bosons on a flat-band lattice above the critical filling factor

dc.contributor.author	Phillips, Lawrence G.
dc.contributor.author	De Chiara, Gabriele
dc.contributor.author	Ohberg, Patrik
dc.contributor.author	Valiente Cifuentes, Manuel
dc.contributor.department	Física
dc.date.accessioned	2025-01-28T09:18:42Z
dc.date.available	2025-01-28T09:18:42Z
dc.date.issued	2015-02-03
dc.description	© 2015 American Physical Society. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published Manuscript, version of a Published Work that appeared in final form in Physical Review B (condensed matter and materials physics). To access the final edited and published work see https://doi.org/10.1103/PhysRevB.91.054103
dc.description.abstract	Bosons interacting repulsively on a lattice with a flat lowest band energy dispersion may, at sufficiently small filling factors, enter into a Wigner-crystal-like phase. This phase is a consequence of the dispersionless nature of the system, which in turn implies the occurrence of single-particle localized eigenstates. We investigate one of these systems—the sawtooth lattice—filled with strongly repulsive bosons at filling factors infinitesimally above the critical point where the crystal phase is no longer the ground state. We find, in the hard-core limit, that the crystal retains its structure in all but one of its cells, where it is broken. The broken cell corresponds to an exotic kind of repulsively bound state, which becomes delocalized. We investigate the excitation spectrum of the system analytically and find that the bound state behaves as a single particle hopping on an effective lattice with reduced periodicity, and is therefore gapless. Thus, the addition of a single particle to a flat-band system at critical filling is found to be enough to make kinetic behavior manifest.
dc.format	application/pdf	es
dc.identifier.citation	Physical Review B, Vol. 91, 054103 (2015)
dc.identifier.doi	https://doi.org/10.1103/PhysRevB.91.054103
dc.identifier.issn	Print: 2469-9950
dc.identifier.issn	Electronic: 2469-9969
dc.identifier.uri	http://hdl.handle.net/10201/149410
dc.language	eng	es
dc.publisher	American Physical Society
dc.relation	EPSRC CM-DTC, EPSRC Grant No. EP/J001392/1, EPSRC (EP/L005026/1 and EP/K029371/1), the John Tem- pleton Foundation (Grant ID 43467), and the EU Collaborative Project TherMiQ (Grant Agreement 618074).	es
dc.relation.publisherversion	https://journals.aps.org/prb/abstract/10.1103/PhysRevB.91.054103
dc.rights	info:eu-repo/semantics/openAccess	es
dc.rights	Attribution-NonCommercial-NoDerivatives 4.0 Internacional	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/4.0/	*
dc.subject.other	CDU::5 - Ciencias puras y naturales	es
dc.title	Low-energy behavior of strongly interacting bosons on a flat-band lattice above the critical filling factor	es
dc.type	info:eu-repo/semantics/article	es
dspace.entity.type	Publication	es