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arXiv · 1505.06801

Reduced Dimensionality and Magnetic Frustration in KCr$_3$As$_3$

Chao Cao·Hao Jiang·Xiao-Yong Feng·Jianhui Dai
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Abstract

We study the electronic and magnetic structures of the newly-discovered compound KCr$_3$As$_3$. The non-magnetic state has five Fermi surface sheets involving respectively three quasi-one-dimensional and two three-dimensional energy bands. However, the ground state is magnetic, exhibiting a novel interlayer antiferromagnetic order where the basic block-spin state of a unit Cr triangle retains a high spin magnitude. Moreover, its Fermi surface involves three one-dimensional sheets only, providing evidence for local moments in this compound due to the reduced dimensionality. By fitting a twisted spin tube model the magnetic frustrations caused by local moments are found to be relaxed, leading to gapless spin excitations. A frustration-induced transition to the disordered low block-spin state is expected upon increasing the intralayer exchange interaction.

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Chao Cao, Hao Jiang, Xiao-Yong Feng, Jianhui Dai. 2015-05-26. Reduced Dimensionality and Magnetic Frustration in KCr$_3$As$_3$. https://doi.org/10.1103/physrevb.92.235107

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