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arXiv 1708.02584cond-mat.str-el
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自旋液体层间热输运的分馏特征

Signatures of fractionalization in spin liquids from interlayer thermal transport

Yochai Werman, Shubhayu Chatterjee, Siddhardh C. Morampudi, Erez Berg

摘要:

量子自旋液体(QSL)是具有分数激发态的物质的有趣相态。一些准二维材料已被提出作为候选QSL,但在这些系统中的分馏的直接证据仍然缺乏。在本文中,我们表明,在层状QSL的面间热导率进行了独特的签名的分馏。我们研究了几种类型的无带隙QSL阶段-一个$Z_2$ QSL与狄拉克光谱或自旋费米表面,和一个$U(1)$ QSL与费米表面。在所有情况下,平面内和$c-$轴的热导率具有不同的幂律依赖于温度,由于在两个方向上的不同的传输机制:在平面中,热电流由分数激发携带,而平面间电流由整数(非分数)激发携带。在具有费米面的层状$Z_2$和$U(1)$ QSL中,$c-$轴向热导率在参数上小于面内热导率,但在参数上大于低温下声子贡献。

英文摘要:

Quantum spin liquids (QSLs) are intriguing phases of matter possessing fractionalized excitations. Several quasi-two dimensional materials have been proposed as candidate QSLs, but direct evidence for fractionalization in these systems is still lacking. In this paper, we show that the inter-plane thermal conductivity in layered QSLs carries a unique signature of fractionalization. We examine several types of gapless QSL phases - a $Z_2$ QSL with either a Dirac spectrum or a spinon Fermi surface, and a $U(1)$ QSL with a Fermi surface. In all cases, the in-plane and $c-$axis thermal conductivities have a different power law dependence on temperature, due to the different mechanisms of transport in the two directions: in the planes, the thermal current is carried by fractionalized excitations, whereas the inter-plane current is carried by integer (non-fractional) excitations. In layered $Z_2$ and $U(1)$ QSLs with a Fermi surface, the $c-$axis thermal conductivity is parametrically smaller than the in-plane one, but parametrically larger than the phonon contribution at low temperatures.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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