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Magnetism and Hund's rule in an optical lattice with cold fermions

Kärkkäinen, Kimmo LU ; Borgh, Magnus LU ; Manninen, M. and Reimann, Stephanie LU (2007) In New Journal of Physics 9.
Abstract
We demonstrate that a two-dimensional (2D) optical lattice loaded with repulsive, contact-interacting fermions shows a rich and systematic magnetic phase diagram. Trapping a few (N <= 12) fermions in each of the single-site minima of the optical lattice, we find that the shell structure in these quantum wells determines the magnetism. In a shallow lattice, the tunnelling between the single wells is strong, and the lattice is non-magnetic (NM). For deeper lattices, however, the shell filling of the single wells with fermionic atoms determines the magnetism. As a consequence of Hund's first rule, the interaction energy is lowered by maximizing the number of atoms of the same species. This leads to a systematic sequence of NM,... (More)
We demonstrate that a two-dimensional (2D) optical lattice loaded with repulsive, contact-interacting fermions shows a rich and systematic magnetic phase diagram. Trapping a few (N <= 12) fermions in each of the single-site minima of the optical lattice, we find that the shell structure in these quantum wells determines the magnetism. In a shallow lattice, the tunnelling between the single wells is strong, and the lattice is non-magnetic (NM). For deeper lattices, however, the shell filling of the single wells with fermionic atoms determines the magnetism. As a consequence of Hund's first rule, the interaction energy is lowered by maximizing the number of atoms of the same species. This leads to a systematic sequence of NM, ferromagnetic (F) and antiferromagnetic (AF) phases. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
New Journal of Physics
volume
9
article number
33
publisher
IOP Publishing
external identifiers
  • wos:000244400400001
  • scopus:33847234283
ISSN
1367-2630
DOI
10.1088/1367-2630/9/2/033
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Mathematical Physics (Faculty of Technology) (011040002)
id
98a4f9d7-1e72-4b76-91b8-7281bf1ad21e (old id 674484)
date added to LUP
2016-04-01 16:14:09
date last changed
2022-01-28 18:17:37
@article{98a4f9d7-1e72-4b76-91b8-7281bf1ad21e,
  abstract     = {{We demonstrate that a two-dimensional (2D) optical lattice loaded with repulsive, contact-interacting fermions shows a rich and systematic magnetic phase diagram. Trapping a few (N &lt;= 12) fermions in each of the single-site minima of the optical lattice, we find that the shell structure in these quantum wells determines the magnetism. In a shallow lattice, the tunnelling between the single wells is strong, and the lattice is non-magnetic (NM). For deeper lattices, however, the shell filling of the single wells with fermionic atoms determines the magnetism. As a consequence of Hund's first rule, the interaction energy is lowered by maximizing the number of atoms of the same species. This leads to a systematic sequence of NM, ferromagnetic (F) and antiferromagnetic (AF) phases.}},
  author       = {{Kärkkäinen, Kimmo and Borgh, Magnus and Manninen, M. and Reimann, Stephanie}},
  issn         = {{1367-2630}},
  language     = {{eng}},
  publisher    = {{IOP Publishing}},
  series       = {{New Journal of Physics}},
  title        = {{Magnetism and Hund's rule in an optical lattice with cold fermions}},
  url          = {{http://dx.doi.org/10.1088/1367-2630/9/2/033}},
  doi          = {{10.1088/1367-2630/9/2/033}},
  volume       = {{9}},
  year         = {{2007}},
}