TY - JOUR
T1 - On the existence of a gap in the energy spectrum of quantum systems
AU - Caspers, W.J.
AU - Magnus, W.
PY - 1983
Y1 - 1983
N2 - A theorem on the existence of a gap in the energy spectrum of quantum systems, the exact ground state of which is known explicitly, is proved. The theorem is applied to a three-dimensional Heisenberg spin-1/2 ferromagnet, with anisotropic nearest-neighbour interactions, and to an alternating Heisenberg antiferromagnet, with nearest- and next-nearest-neighbour interactions.
AB - A theorem on the existence of a gap in the energy spectrum of quantum systems, the exact ground state of which is known explicitly, is proved. The theorem is applied to a three-dimensional Heisenberg spin-1/2 ferromagnet, with anisotropic nearest-neighbour interactions, and to an alternating Heisenberg antiferromagnet, with nearest- and next-nearest-neighbour interactions.
U2 - 10.1088/0022-3719/16/33/012
DO - 10.1088/0022-3719/16/33/012
M3 - Article
SN - 0022-3719
VL - 16
SP - 6395
JO - Journal of Physics C: Solid State Physics
JF - Journal of Physics C: Solid State Physics
IS - 33
ER -