Topological Lifshitz transitions and Fermi arc manipulation in Weyl semimetal NbAs
ORAL
Abstract
Surface Fermi arcs (SFAs), the unique open Fermi-surfaces (FSs) discovered recently in topological Weyl semimetals (TWSs), are unlike closed FSs in conventional materials and can give rise to many exotic phenomena, such as anomalous SFA-mediated quantum oscillations, chiral magnetic effects, three-dimensional quantum Hall effect, non-local voltage generation and anomalous electromagnetic wave transmission. Here, by using in-situ surface decoration, we demonstrate successful manipulation of the shape, size and even the connections of SFAs in a model TWS, NbAs, and observe their evolution that leads to an
unusual topological Lifshitz transition not caused by the change of the carrier concentration. The phase transition teleports the SFAs between different parts of the surface Brillouin zone. Despite the dramatic surface evolution, the existence of SFAs is robust and each SFA remains tied to a pair of Weyl points of opposite chirality, as dictated by the bulk topology.
unusual topological Lifshitz transition not caused by the change of the carrier concentration. The phase transition teleports the SFAs between different parts of the surface Brillouin zone. Despite the dramatic surface evolution, the existence of SFAs is robust and each SFA remains tied to a pair of Weyl points of opposite chirality, as dictated by the bulk topology.
*This work was supported by the National Key R&D program of China (No. 2017YFA0305400), the National Natural Science Foundation of China (Grants No. 11774190, No. 11674229 and No. 11634009). Y.L.C. acknowledges the support of the EPSRC Platform Grant (Grant No EP/M020517/1) and Hefei Science Center CAS (2015HSC-UE013).
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Presenters
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Haifeng Yang
- ShanghaiTech University