Proximate ferromagnetic state in the Kitaev model material α-RuCl(3).
Proximate ferromagnetic state in the Kitaev model material α-RuCl(3).
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DOI：
10.1038/s41467-021-24722-4
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发表时间：
2021-07-23
影响因子：
16.6
通讯作者：
Keimer B
中科院分区：
文献类型：
--
作者：
Suzuki H;Liu H;Bertinshaw J;Ueda K;Kim H;Laha S;Weber D;Yang Z;Wang L;Takahashi H;Fürsich K;Minola M;Lotsch BV;Kim BJ;Yavaş H;Daghofer M;Chaloupka J;Khaliullin G;Gretarsson H;Keimer B
α-RuCl3是实现Kitaev量子自旋液体的主要候选者，但其在低温下的锯齿状反铁磁序表明偏离了Kitaev模型。我们用共振非弹性x射线散射研究了α-RuCl3的自旋哈密顿量。在顺磁状态下，磁激发的准弹性强度在区中心附近有一个很宽的极大值，而在锯齿形磁Bragg波矢没有出现任何局部极大值。这一发现表明，之字形有序是脆弱的，很容易被竞争的铁磁关联所破坏。实验确定的哈密顿量的经典基态实际上是铁磁性的。之字态由量子涨落稳定，留下铁磁性--以及Kitaev自旋液体--作为能量接近的亚稳态。这三个相互竞争的态及其集体激发是从理论上理解α-RuCl3在磁场中的异常性质的关键。在寻找量子自旋液体方面，RuCl3已经脱颖而出；然而，它在低温下的反铁磁有序表明它偏离了典型的QSL模型。本文利用共振非弹性x射线散射，全面测定了低能有效哈密顿量。
α-RuCl3 is a major candidate for the realization of the Kitaev quantum spin liquid, but its zigzag antiferromagnetic order at low temperatures indicates deviations from the Kitaev model. We have quantified the spin Hamiltonian of α-RuCl3 by a resonant inelastic x-ray scattering study at the Ru L3 absorption edge. In the paramagnetic state, the quasi-elastic intensity of magnetic excitations has a broad maximum around the zone center without any local maxima at the zigzag magnetic Bragg wavevectors. This finding implies that the zigzag order is fragile and readily destabilized by competing ferromagnetic correlations. The classical ground state of the experimentally determined Hamiltonian is actually ferromagnetic. The zigzag state is stabilized by quantum fluctuations, leaving ferromagnetism – along with the Kitaev spin liquid – as energetically proximate metastable states. The three closely competing states and their collective excitations hold the key to the theoretical understanding of the unusual properties of α-RuCl3 in magnetic fields. RuCl3 has stood out as a prime candidate in the search for quantum spin liquids; however, its antiferromagnetic ordering at low temperature suggests deviations from typical QSL models. Here, using resonant inelastic x-ray scattering, the authors provide a comprehensive determination of the low energy effective Hamiltonian.
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影响因子：
--
作者：
Khaliullin, G
通讯作者：
Khaliullin, G
影响因子：
8.6
作者：
Gretarsson, H.;Clancy, J. P.;Kim, Young-June
通讯作者：
Kim, Young-June
影响因子：
5.7
作者：
Banerjee, Arnab;Lampen-Kelley, Paula;Nagler, Stephen E.
通讯作者：
Nagler, Stephen E.
影响因子：
8.6
作者：
Chaloupka, Jiri;Jackeli, George;Khaliullin, Giniyat
通讯作者：
Khaliullin, Giniyat
影响因子：
3.7
作者：
Gretarsson, H.;Suzuki, H.;Keimer, B.
通讯作者：
Keimer, B.