Comparison of the iterated equation of motion approach and the density matrix formalism for the quantum Rabi model
| Autor: | H. Krull, Götz S. Uhrig, Mona H. Kalthoff, Frederik Keim |
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| Rok vydání: | 2017 |
| Předmět: |
Strongly Correlated Electrons (cond-mat.str-el)
Truncation FOS: Physical sciences Bilinear interpolation Equations of motion Observable Condensed Matter Physics 01 natural sciences Rotation formalisms in three dimensions 010305 fluids & plasmas Electronic Optical and Magnetic Materials Condensed Matter - Strongly Correlated Electrons Iterated function 0103 physical sciences Statistical physics 010306 general physics Quantum Hamiltonian (control theory) Mathematics |
| Zdroj: | The European Physical Journal B. 90 |
| ISSN: | 1434-6036 1434-6028 |
| Popis: | The density matrix formalism and the equation of motion approach are two semi-analytical methods that can be used to compute the non-equilibrium dynamics of correlated systems. While for a bilinear Hamiltonian both formalisms yield the exact result, for any non-bilinear Hamiltonian a truncation is necessary. Due to the fact that the commonly used truncation schemes differ for these two methods, the accuracy of the obtained results depends significantly on the chosen approach. In this paper, both formalisms are applied to the quantum Rabi model. This allows us to compare the approximate results and the exact dynamics of the system and enables us to discuss the accuracy of the approximations as well as the advantages and the disadvantages of both methods. It is shown to which extent the results fulfill physical requirements for the observables and which properties of the methods lead to unphysical results. Comment: 13 pages, 4 figures |
| Databáze: | OpenAIRE |
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