Quantum Hall effect of Weyl fermions in n-type semiconducting tellurene

Abstract

The advent of graphene has evoked the re-examination of band topology of Dirac/Weyl nodal materials which can host low-energy realistic quasiparticles. Under strong magnetic fields, the topological properties of two-dimensional Dirac/Weyl materials can be directly manifested through quantum Hall states. Here we report the first observation of massive Weyl fermions through quantum Hall effect in n-type Weyl semiconductor tellurene (two-dimensional form of tellurium). The n-type doping profile forms a wide quantum well in tellurene, where two correlated layers of electrons create a pair of symmetric-antisymmetric energy states in addition to spin and valley degeneracy, leading to an approximate SU(8) isospin symmetry. The chirality-induced Weyl nodes residing near the edge of the conduction band give rise to radial spin texture, and topologically non-trivial  Berry phase was detected in quantum Hall sequences. Our work presents strong evidence of massive Weyl fermions and expands the spectrum of Weyl matters into semiconductor regime.

Strain‐Engineered Anisotropic Optical and Electrical Properties in 2D Chiral‐Chain Tellurium

“…2D tellurium (Te), an emerging 2D semiconductor, [ 41 ] boasts attractive characteristics, such as high carrier mobility, large electro‐optic activity, superior air‐stability, strong spin–orbit interaction, chirality‐induced Weyl nodes, etc. [ 42–44,38,45,41,46,47 ] 2D Te's intriguing structure [ 48,45,41,49 ] consists of an anisotropic chiral‐chain crystal lattice. Each Te atom is covalently bonded with its two nearest neighbors on the same chain, and the interchain interaction is weaker than the covalent bond.…”

A high performance self-powered photodetector based on a 1D Te–2D WS2 mixed-dimensional heterostructure

“…The heterostructures based phototransistors displayed obvious anti-ambipolar transport and rectification behavior as well as a high photoresponsivity of 10 3 A/W and a fast response time of 15 ms under 1550 nm communication wavelength [29]. Above all, a number of research groups have focused on the spintronic, electronic and photo-response properties of Te nanosheet and nanowire [30][31][32][33][34][35][36][37][38], while the photodetection properties of Te microwire based mixeddimensional heterostructure is rarely reported. Noticeably, the large dark current and ultrafast electron-hole recombination rate of Te are the main disadvantages for further application because of the narrow band gap of Te in bulk.…”

Study of the Growth Mechanism of Solution‐Synthesized Symmetric Tellurium Nanoflakes at Atomic Resolution

“…Recently, as a new member of 2D materials, 2D Te has drawn much attention from researchers. Theoretical calculations and experiments reveal its promising physical and chemical properties, [ 17–24 ] such as high carrier mobilities, [ 17–19 ] tunable bandgap (which is inversely proportional to the number of layers), [ 18,20 ] and good air‐stability at room temperature, [ 18,20,21 ] which make it a potential candidate for applications in electronics and optoelectronic devices. Nanodevices based on 2D Te have been reported to achieve outstanding performance.…”