10 research outputs found
One-dimensional fermionic systems after interaction quenches and their description by bosonic field theories
We show that the dynamics of quenches in one dimension far off equilibrium
can be described by power laws, but with exponents differing from the fully
renormalized ones at lowest energies. Instead they depend on the initial state
and its excitation energy. Furthermore, we found that for quenches to strong
interactions unexpected similarities between systems in one and in infinite
dimensions occur, indicating the dominance of local processes.Comment: This is a distinctly revised version which is focussed on the
description of the dynamics by bosonization technique
Adapted continuous unitary transformation to treat systems with quasiparticles of finite lifetime
An improved generator for continuous unitary transformations is introduced to
describe systems with unstable quasiparticles. Its general properties are
derived and discussed. To illustrate this approach we investigate the
asymmetric antiferromagnetic spin-1/2 Heisenberg ladder which allows for
spontaneous triplon decay. We present results for the low energy spectrum and
the momentum resolved spectral density of this system. In particular, we show
the resonance behavior of the decaying triplon explicitly.Comment: 40 pages, 12 figure
Hole Dispersions for Antiferromagnetic Spin-1/2 Two-Leg Ladders by Self-Similar Continuous Unitary Transformations
The hole-doped antiferromagnetic spin-1/2 two-leg ladder is an important
model system for the high- superconductors based on cuprates. Using the
technique of self-similar continuous unitary transformations we derive
effective Hamiltonians for the charge motion in these ladders. The key
advantage of this technique is that it provides effective models explicitly in
the thermodynamic limit. A real space restriction of the generator of the
transformation allows us to explore the experimentally relevant parameter
space. From the effective Hamiltonians we calculate the dispersions for single
holes. Further calculations will enable the calculation of the interaction of
two holes so that a handle of Cooper pair formation is within reach.Comment: 16 pages, 26 figure
The triplet gemcitabine (G), epirubicin (E) and docetaxel (Doc) is feasible, safe and highly active as primary systemic therapy (PST) of patients (pts) with multicentric phase I/II trial
Studien �ber den Ablauf der Alkoholintoxikation unter besonderer Ber�cksichtigung der pharmakopsychologischen Beziehungen in der Resorptionsphase bei Alkoholgew�hnten
Time-dependent Mott transition in the periodic Anderson model with nonlocal hybridization
Truncation errors in self-similar continuous unitary transformations
Effects of truncation in self-similar continuous unitary transformations (S-CUT) are estimated rigorously. We find a formal description via an inhomogeneous flow equation. In this way, we are able to quantify truncation errors within the framework of the S-CUT and obtain rigorous error bounds for the ground state energy and the highest excited level. These bounds can be lowered exploiting symmetries of the Hamiltonian. We illustrate our approach with results for a toy model of two interacting hard-core bosons and the dimerized S=1/2 Heisenberg chain. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011