Optimizing linked-cluster expansions by white graphs

Coester K, Schmidt KP (2015)

Publication Status: Published

Publication Type: Journal article

Publication year: 2015

Journal

Physical Review E American Physical Society

Publisher: AMER PHYSICAL SOC

Book Volume: 92

Journal Issue: 2

DOI: 10.1103/PhysRevE.92.022118

Abstract

We introduce a white-graph expansion for the method of perturbative continuous unitary transformations when implemented as a linked-cluster expansion. The essential idea behind an expansion in white graphs is to perform an optimized bookkeeping during the calculation by exploiting the model-independent effective Hamiltonian in second quantization and the associated inherent cluster additivity. This approach is shown to be especially well suited for microscopic models with many coupling constants, since the total number of relevant graphs is drastically reduced. The white-graph expansion is exemplified for a two-dimensional quantum spin model of coupled two-leg XXZ ladders.

Authors with CRIS profile

Kai Phillip Schmidt Professur für Theoretische Physik

Involved external institutions

Technische Universität Dortmund DE Germany (DE)

How to cite

APA:

Coester, K., & Schmidt, K.P. (2015). Optimizing linked-cluster expansions by white graphs. Physical Review E, 92(2). https://doi.org/10.1103/PhysRevE.92.022118

MLA:

Coester, K., and Kai Phillip Schmidt. "Optimizing linked-cluster expansions by white graphs." Physical Review E 92.2 (2015).

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