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Multi-scale Extensions to Quantum Cluster Methods for Strongly Correlated Electron Systems

C. Slezak·M. Jarrell·Th. Maier·J. Deisz
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Abstract

A numerically implementable Multi-scale Many-Body approach to strongly correlated electron systems is introduced. An extension to quantum cluster methods, it approximates correlations on any given length-scale commensurate with the strength of the correlations on the respective scale. Short length-scales are treated explicitly, long ones are addressed at a mean-field level and intermediate length-regime correlations are assumed to be weak and are approximated diagrammatically. To illustrate and test this method, we apply it to the one dimensional Hubbard model. The resulting multi-scale self-energy provides a very good quantitative agreement with substantially more numerically expensive, explicit Quantum Monte-Carlo calculations.

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C. Slezak, M. Jarrell, Th. Maier, J. Deisz. 2006-09-12. Multi-scale Extensions to Quantum Cluster Methods for Strongly Correlated Electron Systems. https://doi.org/10.1088/0953-8984%2F21%2F43%2F435604

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