241 citations · 953 across the 17 of their papers we have counts for
17 papers
High Order Perturbation Theory for Spectral Densities of Multi-Particle Excitations: S=1/2 Two-Leg Heisenberg Ladder
Christian Knetter, Kai P. Schmidt, Götz S. Uhrig
We present a high order perturbation approach to quantitatively calculate spectral densities in three distinct steps starting from the model Hamiltonian and the observables of inte…
Dynamic Structure Factor of the Two-Dimensional Shastry-Sutherland Model
Christian Knetter, Goetz S. Uhrig
We calculate the 2-triplon contribution to the dynamic structure factor of the 2-dimensional Shastry-Sutherland model, realized in SrCu2(BO3)2, by means of perturbative continuous…
Spectral properties of the dimerized and frustrated chain
Kai P. Schmidt, Christian Knetter, Götz S. Uhrig
Spectral densities are calculated for the dimerized and frustrated S=1/2 chain using the method of continuous unitary transformations (CUTs). The transformation to an effective tri…
The Structure of Operators in Effective Particle-Conserving Models
Christian Knetter, Kai P. Schmidt, Goetz S. Uhrig
For many-particle systems defined on lattices we investigate the global structure of effective Hamiltonians and observables obtained by means of a suitable basis transformation. We…
Charge order induced sharp Raman peak in Sr_14Cu_24O_41
K. P. Schmidt, C. Knetter, M. Grüninger +1
In the two-leg S=1/2 ladders of Sr_14Cu_24O_41 a modulation of the exchange coupling arises from the charge order within the other structural element, the CuO_2 chains. In general,…
Novel Extrapolation for Strong Coupling Expansions
K. P. Schmidt, C. Knetter, G. S. Uhrig
We present a novel extrapolation scheme for high order series expansions. The idea is to express the series, obtained in orders of an external variable, in terms of an internal par…