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arXiv · 2307.12093

Spinon continuum in the Heisenberg quantum chain compound Sr$_2$V$_3$O$_9$

Shang Gao·Ling-Fang Lin·Pontus Laurell·Qiang Chen·Qing Huang·Clarina dela Cruz·Krishnamurthy V. Vemuru·Mark D. Lumsden·Stephen E. Nagler·Gonzalo Alvarez·Elbio Dagotto·Haidong Zhou·Andrew D. Christianson·Matthew B. Stone
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Abstract

Magnetic excitations in the spin chain candidate Sr$_2$V$_3$O$_9$ have been investigated by inelastic neutron scattering on a single crystal sample. A spinon continuum with a bandwidth of $\sim22$ meV is observed along the chain formed by alternating magnetic V$^{4+}$ and nonmagnetic V$^{5+}$ ions. Incipient magnetic Bragg peaks due to weak ferromagnetic interchain couplings emerge when approaching the magnetic transition at $T_N\sim 5.3$ K while the excitations remain gapless within the instrumental resolution. Comparisons to the Bethe ansatz, density matrix renormalization group (DMRG) calculations, and effective field theories confirm Sr$_2$V$_3$O$_9$ as a host of weakly coupled $S = 1/2$ chains dominated by antiferromagnetic intrachain interactions of $\sim7.1$(1) meV.

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Shang Gao, Ling-Fang Lin, Pontus Laurell, Qiang Chen, Qing Huang, Clarina dela Cruz, Krishnamurthy V. Vemuru, Mark D. Lumsden, Stephen E. Nagler, Gonzalo Alvarez, Elbio Dagotto, Haidong Zhou, Andrew D. Christianson, Matthew B. Stone. 2023-07-22. Spinon continuum in the Heisenberg quantum chain compound Sr$_2$V$_3$O$_9$. https://doi.org/10.1103/physrevb.109.l020402

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