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Cluster truncated Wigner approximation for bond-disordered Heisenberg spin models

We present a comprehensive numerical investigation of the cluster truncated Wigner approximation (cTWA) applied to quench dynamics in bond-disordered Heisenberg spin chains with power-law interactions. We find that cTWA yields highly accurate results over a wide parameter range. However, its accurac...

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Bibliographic Details
Main Authors: Braemer, Adrian (Author) , Vahedi, Javad (Author) , Gärttner, Martin (Author)
Format: Article (Journal)
Language:English
Published: 1 August 2024
In: Physical review
Year: 2024, Volume: 110, Issue: 5, Pages: 054204-1-054204-14
ISSN:2469-9969
DOI:10.1103/PhysRevB.110.054204
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/PhysRevB.110.054204
Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/PhysRevB.110.054204
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Author Notes:Adrian Braemer, Javad Vahedi, and Martin Gärttner
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Summary:We present a comprehensive numerical investigation of the cluster truncated Wigner approximation (cTWA) applied to quench dynamics in bond-disordered Heisenberg spin chains with power-law interactions. We find that cTWA yields highly accurate results over a wide parameter range. However, its accuracy hinges on a suitable choice of clusters. By using a clustering strategy inspired by the strong disorder renormalization group and real-space renormalization group (RSRG), clusters of two spins are sufficient to obtain essentially exact results in the regime of strong disorder. Surprisingly, even for rather weak disorder, e.g., in the presence of very long-range interactions, this choice of clustering outperforms a naive choice of clusters of consecutive spins. Additionally, we develop a discrete sampling scheme for the initial Wigner function, as an alternative to the originally introduced scheme based on Gaussian approximations. This sampling scheme puts cTWA on the same conceptional footing as regular discrete TWA for single spins and yields some reduction in the Monte Carlo shot noise compared to the Gaussian scheme.
Item Description:Veröffentlicht: 19. August 2024
Gesehen am 20.03.2025
Physical Description:Online Resource
ISSN:2469-9969
DOI:10.1103/PhysRevB.110.054204

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