Repulsive Casimir force between Weyl semimetals
Repulsive Casimir force between Weyl semimetals
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DOI：
10.1103/physrevb.91.235115
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发表时间：
2015-01
影响因子：
3.7
通讯作者：
Justin H. Wilson;Andrew A. Allocca;V. Galitski
中科院分区：
文献类型：
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作者：
Justin H. Wilson;Andrew A. Allocca;V. Galitski
外尔半金属是一类由于时间反演对称破缺而表现出体霍尔效应的拓扑材料。我们证明了在理想半无限情形下，两个相同的Weyl半金属之间的Casimir力在短程是排斥的，在长程是吸引的。考虑有限厚度的板，我们可以减小长程吸引力的大小，甚至当足够薄时，使其对所有距离都是排斥的。在薄膜的限制，我们研究了一个有吸引力的卡西米尔力在较短的距离，由于纵向导电性的外观。磁场、厚度和化学势为这种效应提供了可调的节点，控制着卡西米尔力：它是吸引力还是排斥力，效应的大小，以及陷阱和反陷阱的位置和存在。
Weyl semimetals are a class of topological materials that exhibit a bulk Hall effect due to time-reversal symmetry breaking. We show that for the idealized semi-infinite case, the Casimir force between two identical Weyl semimetals is repulsive at short range and attractive at long range. Considering plates of finite thickness, we can reduce the size of the long-range attraction even making it repulsive for all distances when thin enough. In the thin-film limit, we study the appearance of an attractive Casimir force at shorter distances due to the longitudinal conductivity. Magnetic field, thickness, and chemical potential provide tunable nobs for this effect, controlling the Casimir force: whether it is attractive or repulsive, the magnitude of the effect, and the positions and existence of a trap and antitrap.