The ground state of XY chains with nearest and next-nearest neighbour interactions
Physics and Astronomy
The ground state of chains with antiferromagnetic XY interactions is examined by direct diagonalisation of the Hamiltonian. Attention is focussed on chains with nearest and next-nearest neighbour interactions. It is found that results for finite chains can be readily extrapolated to infinite chains. The dimerised ground state corresponds to a maximum in the energy per spin with respect to the next-nearest neighbour interaction parameter. An alternate normalisation scheme provides additional insight into how the ground state energy depends on the interaction parameters.
Link to Published Version
Thomsen, M. (2012). The ground state of XY chains with nearest and next-nearest neighbour interactions. Philosophical Magazine, 92(1–3), 160–167. doi:10.1080/14786435.2011.614644