We present a detailed study of the low-energy excitations of two existing finite-size realizations of the planar kagomé Heisenberg antiferromagnet on the sphere: the cuboctahedron and the icosidodecahedron. After highlighting a number of special spectral features (such as the presence of low-lying singlets below the first triplet and the existence of localized magnons) we focus on two major issues. The first concerns the nature of the excitations above the plateau phase at 13 of the saturation magnetization Ms. Our exact diagonalizations for the s=12 icosidodecahedron reveal that the low-lying plateau states are adiabatically connected to the degenerate collinear "up-up-down" ground states of the Ising point, at the same time being well iso...
We discuss the ground state, the low-lying excitations as well as high-eld thermodynamics of the Hei...
The spin wave excitations of the S=5/2 kagomé lattice antiferromagnet KFe3(OH)6(SO4)2 have been meas...
We study the ground state properties of a quantum antiferromagnet on the kagom\'e lattice in the pre...
We study the formation of magnetic clusters in frustrated magnets in their cooperative paramagnetic ...
Kihara T, Nojiri H, Narumi Y, et al. Evidence of low-energy singlet excited states in the spin-1/2 p...
In this thesis, the magnetic properties of geometrically frustrated systems have been studied, using...
We compute ground-state properties of the isotropic, antiferromagnetic Heisenberg model on the sodal...
We identify a class of zero-dimensional classical and quantum Heisenberg spin systems exhibiting ano...
21 pages, 24 figuresThe SrCr$_{9p}$Ga$_{12-9p}$O$_{19}$ and Ba$_{2}$Sn$_{2}$ZnGa$_{10-7p}$Cr$_{7p}$O...
10 pagesUsing magnetization, specific heat and neutron scattering measurements, as well as exact cal...
Membres du jury: Benoit Doucot (Rapporteur), Claudine Lacroix (Rapporteur), Claire Lhuillier (Examin...
The spin wave excitations of the S = 5/2 kagomé lattice antiferromagnet KFe3(OH)6(SO4)2 have been me...
For the paradigmatic frustrated spin-half Heisenberg antiferromagnet on the kagome lattice we perfor...
We explore the phase diagram and the low-energy physics of three Heisenberg antiferromagnets which, ...
The extended kagome lattice, composed of alternating kagome and triangular layers, provides a novel...
We discuss the ground state, the low-lying excitations as well as high-eld thermodynamics of the Hei...
The spin wave excitations of the S=5/2 kagomé lattice antiferromagnet KFe3(OH)6(SO4)2 have been meas...
We study the ground state properties of a quantum antiferromagnet on the kagom\'e lattice in the pre...
We study the formation of magnetic clusters in frustrated magnets in their cooperative paramagnetic ...
Kihara T, Nojiri H, Narumi Y, et al. Evidence of low-energy singlet excited states in the spin-1/2 p...
In this thesis, the magnetic properties of geometrically frustrated systems have been studied, using...
We compute ground-state properties of the isotropic, antiferromagnetic Heisenberg model on the sodal...
We identify a class of zero-dimensional classical and quantum Heisenberg spin systems exhibiting ano...
21 pages, 24 figuresThe SrCr$_{9p}$Ga$_{12-9p}$O$_{19}$ and Ba$_{2}$Sn$_{2}$ZnGa$_{10-7p}$Cr$_{7p}$O...
10 pagesUsing magnetization, specific heat and neutron scattering measurements, as well as exact cal...
Membres du jury: Benoit Doucot (Rapporteur), Claudine Lacroix (Rapporteur), Claire Lhuillier (Examin...
The spin wave excitations of the S = 5/2 kagomé lattice antiferromagnet KFe3(OH)6(SO4)2 have been me...
For the paradigmatic frustrated spin-half Heisenberg antiferromagnet on the kagome lattice we perfor...
We explore the phase diagram and the low-energy physics of three Heisenberg antiferromagnets which, ...
The extended kagome lattice, composed of alternating kagome and triangular layers, provides a novel...
We discuss the ground state, the low-lying excitations as well as high-eld thermodynamics of the Hei...
The spin wave excitations of the S=5/2 kagomé lattice antiferromagnet KFe3(OH)6(SO4)2 have been meas...
We study the ground state properties of a quantum antiferromagnet on the kagom\'e lattice in the pre...