SKM 2023 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 5: Correlated Electrons: Method Development
TT 5.4: Vortrag
Montag, 27. März 2023, 10:15–10:30, HSZ 204
Reduced basis modeling of quantum spin systems based on DMRG — •Paul Brehmer1, Michael Herbst2, Matteo Rizzi3,4, Benjamin Stamm5, and Stefan Wessel1 — 1Institute for Theoretical Solid State Physics, RWTH Aachen University, 52074 Aachen, Germany — 2Applied and Computational Mathematics, RWTH Aachen University, 52062 Aachen, Germany — 3FZ Jülich GmbH, Institute of Quantum Control, Peter Grünberg Institut (PGI-8), 52425 Jülich, Germany — 4Institute for Theoretical Physics, University of Cologne, 50937 Köln, Germany — 5Institute of Applied Analysis and Numerical Simulation, University of Stuttgart, 70569 Stuttgart, Germany
Within the reduced basis modeling approach, an effective low-dimensional subspace of a quantum many-body Hilbert space is constructed in order to investigate, e.g., the ground-state phase diagram. The basis of this subspace is built from solutions of snapshots, i.e., ground states corresponding to particular and well-chosen parameter values. Here, we show how a greedy strategy to assemble the reduced basis and thus to select the parameter points can be implemented based on density-matrix-renormalization-group (DMRG) calculations. Once the reduced basis is computed, observables required for the computation of phase diagrams can be computed with a computational complexity independent of the underlying Hilbert space for any parameter value. We illustrate the efficiency and accuracy of this approach for different one-dimensional quantum spin-S models with both S=1/2 and S=1, including anisotropic as well as biquadratic exchange interactions, leading to rich quantum phase diagrams.