Fractional and composite excitations of antiferromagnetic quantum spin trimer chains
| Autor: | Jun-Qing Cheng, Jun Li, Zijian Xiong, Han-Qing Wu, Anders W. Sandvik, Dao-Xin Yao |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Condensed Matter - Strongly Correlated Electrons
Strongly Correlated Electrons (cond-mat.str-el) TA401-492 FOS: Physical sciences Condensed Matter::Strongly Correlated Electrons Atomic physics. Constitution and properties of matter Condensed Matter Physics Materials of engineering and construction. Mechanics of materials Electronic Optical and Magnetic Materials QC170-197 |
| Zdroj: | npj Quantum Materials, Vol 7, Iss 1, Pp 1-11 (2022) |
| Popis: | Using quantum Monte Carlo, exact diagonalization and perturbation theory, we study the spectrum of the $S=1/2$ antiferromagnetic Heisenberg trimer chain by varying the ratio $g=J_2/J_1$ of the intertrimer and intratrimer coupling strengths. The doublet ground states of trimers form effective interacting $S=1/2$ degrees of freedom described by a Heisenberg chain. Therefore, the conventional two-spinon continuum of width $\propto J_1$ when $g=1$ evolves into to a similar continuum of width $\propto J_2$ when $g\to 0$. The intermediate-energy and high-energy modes are termed \emph{doublons} and \emph{quartons} which fractionalize with increasing $g$ to form the conventional spinon continuum. In particular, at $g \approx 0.716$, the gap between the low-energy spinon branch and the high-energy band with mixed doublons, quartons, and spinons closes. These features should be observable in inelastic neutron scattering experiments if a quasi-one-dimensional quantum magnet with the linear trimer structure and $J_2 Comment: 17pages,11figures |
| Databáze: | OpenAIRE |
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