Dynamics of position-disordered Ising spins with a soft-core potential
We theoretically study the magnetization relaxation of Ising spins distributed randomly in a d-dimension homogeneous and Gaussian profile under a soft-core two-body interaction potential ∝1/[1+(r/Rc)α] (α≥d), where r is the interspin distance and Rc is the soft-core radius. The dynamics starts with...
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| Hauptverfasser: | , , , , , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
23 March 2022
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| In: |
Physical review
Year: 2022, Jahrgang: 105, Heft: 10, Pages: 1-6 |
| ISSN: | 2469-9969 |
| DOI: | 10.1103/PhysRevB.105.104204 |
| Online-Zugang: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/PhysRevB.105.104204 Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/PhysRevB.105.104204 
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| Verfasserangaben: | Canzhu Tan, Xiaodong Lin, Yabing Zhou, Yuhai Jiang, Matthias Weidemüller, and Bing Zhu |
| Zusammenfassung: | We theoretically study the magnetization relaxation of Ising spins distributed randomly in a d-dimension homogeneous and Gaussian profile under a soft-core two-body interaction potential ∝1/[1+(r/Rc)α] (α≥d), where r is the interspin distance and Rc is the soft-core radius. The dynamics starts with all spins polarized in the transverse direction. In the homogeneous case, an analytic expression is derived at the thermodynamic limit, which starts as ∝exp(−kt2) with a constant k and follows a stretched-exponential law at long time with an exponent β=d/α. In between an oscillating behavior is observed with a damping amplitude. For Gaussian samples, the degree of disorder in the system can be controlled by the ratio lρ/Rc, with lρ the mean interspin distance and the magnetization dynamics is investigated numerically. In the limit of lρ/Rc≪1, a coherent many-body dynamics is recovered for the total magnetization despite the position disorder of spins. In the opposite limit of lρ/Rc≫1, a similar dynamics as that in the homogeneous case emerges at a later time after a initial fast decay of the magnetization. We obtain a stretched exponent of β≈0.18 for the asymptotic evolution with d=3,α=6, which is different from that in the homogeneous case (β=0.5). |
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| Beschreibung: | Gesehen am 13.07.2022 |
| Beschreibung: | Online Resource |
| ISSN: | 2469-9969 |
| DOI: | 10.1103/PhysRevB.105.104204 |