The accidental band-crossing origin of Weyl nodes paired with the absence of sizeable band gaps hampers the exploitation of low-energy relativistic quasiparticles in Weyl semimetals. In a gate-tunable high-quality tellurene film, quantum Hall measurements unveil a topologically non-trivial π Berry phase caused by unconventional Weyl nodes in these tellurium two-dimensional sheets.
- Gang Qiu
- Chang Niu
- Peide D. Ye
