Quantum kagomé antiferromagnet in a magnetic field: Low-lying nonmagnetic excitations versus valence-bond crystal order

We study the ground state properties of a quantum antiferromagnet on the kagom\'e lattice in the presence of a magnetic field, paying particular attention to the stability of the plateau at magnetization 1∕3 of saturation and the nature of its ground state. We discuss fluctuations around classi...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Cabra, Daniel Carlos, Grynberg, Marcelo Daniel, Holdsworth, P. C. W., Honecker, A., Pujol, P., Richter, J., Schmalfuß, D., Schulenburg, J.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2005
Materias:
Física
Magnetic field
Physics
Antiferromagnetism
Valence bond theory
Heisenberg model
Condensed matter physics
Spins
Magnetization
Ground state
Degenerate energy levels
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/125858
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-125858
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Física
Magnetic field
Physics
Antiferromagnetism
Valence bond theory
Heisenberg model
Condensed matter physics
Spins
Magnetization
Ground state
Degenerate energy levels
spellingShingle Física
Magnetic field
Physics
Antiferromagnetism
Valence bond theory
Heisenberg model
Condensed matter physics
Spins
Magnetization
Ground state
Degenerate energy levels
Cabra, Daniel Carlos
Grynberg, Marcelo Daniel
Holdsworth, P. C. W.
Honecker, A.
Pujol, P.
Richter, J.
Schmalfuß, D.
Schulenburg, J.
Quantum kagomé antiferromagnet in a magnetic field: Low-lying nonmagnetic excitations versus valence-bond crystal order
topic_facet Física
Magnetic field
Physics
Antiferromagnetism
Valence bond theory
Heisenberg model
Condensed matter physics
Spins
Magnetization
Ground state
Degenerate energy levels
description We study the ground state properties of a quantum antiferromagnet on the kagom\'e lattice in the presence of a magnetic field, paying particular attention to the stability of the plateau at magnetization 1∕3 of saturation and the nature of its ground state. We discuss fluctuations around classical ground states and argue that quantum and classical calculations at the harmonic level do not lead to the same result in contrast to the zero-field case. For spin S=1∕2 we find a magnetic gap below which an exponential number of nonmagnetic excitations are present. Moreover, such non-magnetic excitations also have a (much smaller) gap above the threefold degenerate ground state. We provide evidence that the ground state has long-range order of valence-bond crystal type with nine spins in the unit cell.
format Articulo
Articulo
author Cabra, Daniel Carlos
Grynberg, Marcelo Daniel
Holdsworth, P. C. W.
Honecker, A.
Pujol, P.
Richter, J.
Schmalfuß, D.
Schulenburg, J.
author_facet Cabra, Daniel Carlos
Grynberg, Marcelo Daniel
Holdsworth, P. C. W.
Honecker, A.
Pujol, P.
Richter, J.
Schmalfuß, D.
Schulenburg, J.
author_sort Cabra, Daniel Carlos
title Quantum kagomé antiferromagnet in a magnetic field: Low-lying nonmagnetic excitations versus valence-bond crystal order
title_short Quantum kagomé antiferromagnet in a magnetic field: Low-lying nonmagnetic excitations versus valence-bond crystal order
title_full Quantum kagomé antiferromagnet in a magnetic field: Low-lying nonmagnetic excitations versus valence-bond crystal order
title_fullStr Quantum kagomé antiferromagnet in a magnetic field: Low-lying nonmagnetic excitations versus valence-bond crystal order
title_full_unstemmed Quantum kagomé antiferromagnet in a magnetic field: Low-lying nonmagnetic excitations versus valence-bond crystal order
title_sort quantum kagomé antiferromagnet in a magnetic field: low-lying nonmagnetic excitations versus valence-bond crystal order
publishDate 2005
url http://sedici.unlp.edu.ar/handle/10915/125858
work_keys_str_mv AT cabradanielcarlos quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
AT grynbergmarcelodaniel quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
AT holdsworthpcw quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
AT honeckera quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
AT pujolp quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
AT richterj quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
AT schmalfußd quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
AT schulenburgj quantumkagomeantiferromagnetinamagneticfieldlowlyingnonmagneticexcitationsversusvalencebondcrystalorder
bdutipo_str Repositorios
_version_ 1764820452374478850

Ejemplares similares