Chiral Anomaly-Enhanced Casimir Interaction between Weyl Semimetals
Jia-Nan Rong1,3, Liang Chen2*, and Kai Chang1,3*
1SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China 2School of Mathematics and Physics, North China Electric Power University, Beijing 102206, China 3CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
Abstract：We theoretically study the Casimir interaction between Weyl semimetals. When the distance $a$ between semi-infinite Weyl semimetals is in the micrometer regime, the Casimir attraction can be enhanced by the chiral anomaly. The Casimir attraction depends sensitively on the relative orientations between the separations ($\boldsymbol{b}_1$, $\boldsymbol{b}_2$) of Weyl nodes in the Brillouin zone and show anisotropic behavior for the relative orientation of these separations ($\boldsymbol{b}_1$, $\boldsymbol{b}_2$) when they orient parallel to the interface. This anisotropy is quite larger than that in conventional birefringent materials. The Casimir force can be repulsive in the micrometer regime if the Weyl semimetal slabs are sufficiently thin and the direction of Weyl nodes separations ($\boldsymbol{b}_1$, $\boldsymbol{b}_2$) is perpendicular to the interface. The Casimir attraction between Weyl semimetal slabs decays slower than $1/a^4$ when the Weyl nodes separations $\boldsymbol{b}_1$ and $\boldsymbol{b}_2$ are both parallel to the interface.
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2021, Vol. 38 
