Berlin 2018 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 15: Dual-Method Approaches to Quantum Many-Body Systems I
TT 15.13: Talk
Monday, March 12, 2018, 18:15–18:30, H 0104
New hierarchical quantum master equation approach based on an interaction expansion: A first implementation for an Anderson impurity — •Jakob Bätge1,2 and Rainer Härtle1,2 — 1Institut für theoretische Physik, Georg-August-Universität Göttingen — 2Institute of Physics, University of Freiburg
The description of transport through open quantum systems is important for the quantum information processing or molecular electronics. Physical systems of interest are, for example, several coupled qubits or the voltage profile along a molecule. As the amount of possible states of quantum systems increases exponentially with the number of degrees of freedom, the numerical effort for exact techniques typically increases exponentially with system size. The exact treatment of large systems might open the view on new physical effects. The numerically exact hierarchical quantum master equation approach (HQME)[1-3] is based on a systematically improvable hybridization expansion and predicts the time-evolution of the quantum system. Due to its time-local formulation stationary state properties can be studied. Here we present an extension of the HQME, which includes an additional expansion in the many-body interaction. The new approach focuses on the low-particle reduced density matrices and hence shows a power law dependence on system size. The newly extended HQME is still a numerically exact approach. A first implementation for the well studied Anderson impurity model shows the usefulness of the new method.
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