Multifold Hopf semimetals
| Autor: | Graf, Ansgar, Piéchon, Frédéric |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Condensed Matter - Other Condensed Matter
Condensed Matter - Mesoscale and Nanoscale Physics Mesoscale and Nanoscale Physics (cond-mat.mes-hall) FOS: Physical sciences Condensed Matter::Strongly Correlated Electrons Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Other Condensed Matter (cond-mat.other) |
| Popis: | Three-dimensional topological semimetals exhibit linear energy band crossing points that act as monopoles of Berry curvature. Here, an alternative class of semimetals is introduced, featuring linear $N$-fold crossing points each of which acts as a source of a \emph{Berry dipole}. We construct continuum and lattice models for such \emph{multifold Hopf semimetals (MHSs)} with $N=3,4,5$ bands and study nontrivial effects of a Berry dipole crossing: (i) A Landau level spectrum that is strongly tunable by the orientation of $\mathbf{B}$ relative to the dipole axis. (ii) An anomalous Hall conductivity that is odd in the Fermi level $E_F$. (iii) Weak-field dissipative magnetoconductivities that resemble the chiral anomaly, chiral magnetic and magnetochiral effects familiar from a pair of coupled Weyl nodes, but that are even in $E_F$. By gapping out MHSs, multiband Hopf insulators with Hopf numbers as high as $\mathcal{N}_\text{Hopf}=10$ are obtained, providing a fertile playground to explore delicate topology. Considerably revised version. Comments welcome. 7 + 23 pages, 4 + 4 figures |
| Databáze: | OpenAIRE |
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