711 citations · 5.5k across the 188 of their papers we have counts for
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Landau's quasi-particle mapping: Fermi liquid approach and Luttinger liquid behavior
Caspar P. Heidbrink, Götz S. Uhrig
A continuous unitary transformation is introduced which realizes Landau's mapping of the elementary excitations (quasi-particles) of an interacting Fermi liquid system to those of…
Spin-Phonon Chains with Bond Coupling
Carsten Raas, Ute Löw, Götz S. Uhrig +1
We investigate the antiadiabatic limit of an antiferromagnetic S=1/2 Heisenberg chain coupled to Einstein phonons via a bond coupling. The flow equation method is used to decouple…
Magnetic excitations in two-leg spin 1/2 ladders: experiment and theory
M. Grueninger, M. Windt, T. Nunner +8
Magnetic excitations in two-leg S=1/2 ladders are studied both experimentally and theoretically. Experimentally, we report on the reflectivity, the transmission and the optical con…
Heat transport in SrCu_2(BO_3)_2 and CuGeO_3
M. Hofmann, T. Lorenz, A. Freimuth +5
In the low dimensional spin systems and the thermal conductivities along different crystal directions show pronounced double-peak structures and strongly…
Optical spectroscopy of (La,Ca)14Cu24O41 spin ladders: comparison of experiment and theory
M. Grueninger, M. Windt, T. Nunner +8
Transmission and reflectivity of La_x Ca_14-x Cu_24 O_41 two-leg spin-1/2 ladders were measured in the mid-infrared regime between 500 and 12000 1/cm. This allows us to determine t…
Multi-particle excitations and spectral densities in quantum spin-systems
Christian Knetter, Kai P. Schmidt, Götz S. Uhrig
The excitation spectrum of the 2-leg S=1/2 Heisenberg ladder is examined perturbatively. Using an optimally chosen continuous unitary transformation we expand the Hamiltonian and t…
Raman Response in Antiferromagnetic Two-Leg S=1/2 Heisenberg Ladders
Kai P. Schmidt, Christian Knetter, Götz S. Uhrig
The Raman response in the antiferromagnetic 2-leg S=1/2 Heisenberg ladder is calculated for various couplings by continuous unitary transformations. For leg couplings above 80% of…
Fractional and Integer Excitations in Quantum Antiferromagnetic Spin 1/2 Ladders
C. Knetter, K. P. Schmidt, M. Grüninger +1
Spectral densities are computed in unprecedented detail for quantum antiferromagnetic spin 1/2 two-leg ladders. These results were obtained due to a major methodical advance achiev…
Observation of two-magnon bound states in the two-leg ladders of (Ca,La)14Cu24O41
M. Windt, M. Grueninger, T. Nunner +8
Phonon-assisted 2-magnon absorption is studied at T=4 K in the spin-1/2 two-leg ladders of Ca_14-x La_x Cu_24 O_41 (x=5 and 4) for polarization of the electrical field parallel to…
Strong damping of phononic heat current by magnetic excitations in SrCu_2(BO_3)_2
M. Hofmann, T. Lorenz, G. S. Uhrig +5
Measurements of the thermal conductivity as a function of temperature and magnetic field in the 2D dimer spin system SrCu(BO) are presented. In zero magnetic field the…
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…