146 citations · 278 across the 6 of their papers we have counts for
6 papers
Thermodynamics of a Spin-1/2 Chain Coupled to Einstein Phonons
Alexander Bühler, Götz S. Uhrig, Jaan Oitmaa
A high order series expansion is employed to study the thermodynamical properties of a S=1/2 chain coupled to dispersionless phonons. The results are obtained without truncating th…
Thermodynamic Properties of the Dimerised and Frustrated S=1/2 Chain
Alexander Bühler, Ute Löw, Götz S. Uhrig
By high temperature series expansion, exact diagonalisation and temperature density-matrix renormalisation the magnetic susceptibility and the specific heat of dimeri…
Effective Spin Models for Spin-Phonon Chains by Flow Equations
Carsten Raas, Alexander Bühler, Götz S. Uhrig
We investigate the anti-adiabatic limit of an anti-ferromagnetic S=1/2 Heisenberg chain coupled to Einstein phonons. The flow equation method is used to decouple the spin and the p…
SrCu_2(BO_3)_2 - a Two Dimensional Spin Liquid
Christian Knetter, Alexander Buehler, Erwin Mueller-Hartmann +1
We study an extended Shastry-Sutherland model for SrCu_2(BO_3)_2 and analyze the low lying parts of the energy spectrum by means of a perturbative unitary transformation based on f…
Dispersion and Symmetry of Bound States in the Shastry-Sutherland Model
Christian Knetter, Alexander Buehler, Erwin Mueller-Hartmann +1
Bound states made from two triplet excitations on the Shastry-Sutherland (ShaSu) lattice are investigated. Based on the perturbative unitary transformation by flow equations quanti…
High Temperature Expansion for Frustrated and Unfrustrated S=1/2 Spin Chains
Alexander Buehler, Norbert Elstner, Goetz S. Uhrig
A computer aided high temperature expansion of the magnetic susceptibility and the magnetic specific heat is presented and demonstrated for frustrated and unfrustrated spin chains.…