Magnetic breakdown spectrum of a Kramers–Weyl semimetal

Abstract

We calculate the Landau levels of a Kramers–Weyl semimetal thin slab in a perpendicular magnetic field B. The coupling of Fermi arcs on opposite surfaces broadens the Landau levels with a band width that oscillates periodically in 1/B. We interpret the spectrum in terms of a one-dimensional superlattice induced by magnetic breakdown at Weyl points. The band width oscillations may be observed as 1/B-periodic magnetoconductance oscillations, at weaker fields and higher temperatures than the Shubnikov–de Haas oscillations due to Landau level quantization. No such spectrum appears in a generic Weyl semimetal, the Kramers degeneracy at time-reversally invariant momenta is essential.

Axionic band topology in inversion-symmetric Weyl-charge-density waves

“…Our methodology can be extended to spin-density waves [69,[114][115][116] and CDWs in T -symmetric semimetals, including Dirac [97,117,118], Weyl, and nodal-line semimetals [119][120][121][122], which also exhibit signatures of higher-order topology [55,100,123,124]. Most interestingly, because rotation-and T -symmetric HOTIs [28,56] can be formed from weak stacks of 2D TIs [48,51], rotationsymmetric CDWs in T -symmetric WSMs, such as the CDW in (TaSe 4 ) 2 I [78], may also exhibit nontrivial response effects.…”