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arXiv · 1612.06848

Superconductivity provides access to the chiral magnetic effect of an unpaired Weyl cone

T. E. O'Brien·C. W. J. Beenakker·I. Adagideli
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Abstract

The massless fermions of a Weyl semimetal come in two species of opposite chirality, in two cones of the band structure. As a consequence, the current $j$ induced in one Weyl cone by a magnetic field $B$ (the chiral magnetic effect, CME) is cancelled in equilibrium by an opposite current in the other cone. Here we show that superconductivity offers a way to avoid this cancellation, by means of a flux bias that gaps out a Weyl cone jointly with its particle-hole conjugate. The remaining gapless Weyl cone and its particle-hole conjugate represent a single fermionic species, with renormalized charge $e^\ast$ and a single chirality $\pm$ set by the sign of the flux bias. As a consequence, the CME is no longer cancelled in equilibrium but appears as a supercurrent response $\partial j/\partial B=\pm(e^\ast e/h^2)μ$ along the magnetic field at chemical potential $μ$.

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T. E. O'Brien, C. W. J. Beenakker, I. Adagideli. 2017-02-07. Superconductivity provides access to the chiral magnetic effect of an unpaired Weyl cone. https://doi.org/10.1103/physrevlett.118.207701

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