Hydrogenic spin-valley states of the bromine donor in 2H-MoTe2

Abstract

In semiconductors, the identification of doping atomic elements allowing to encode a qubit within spin states is of intense interest for quantum technologies. In transition metal dichalcogenides semiconductors, the strong spin-orbit coupling produces locked spin-valley states with expected long coherence time. Here we study the substitutional Bromine BrTe dopant in 2H-MoTe2. Electron spin resonance measurements show that this dopant carries a spin with long-lived nanoseconds coherence time. Using scanning tunneling spectroscopy, we find that the hydrogenic wavefunctions associated with the dopant levels have characteristics spatial modulations that result from their hybridization to the Q-valleys of the conduction band. From a Fourier analysis of the conductance maps, we find that the amplitude and phase of the Fourier components change with energy according to the different irreducible representations of the impurity-site point-group symmetry. These results demonstrate that a dopant can inherit the locked spin-valley properties of the semiconductor and so exhibit long spin-coherence time.

Broadband and Flexible Photodiode of a Bromine-Doped Lateral MoTe2 Homojunction

“…The bromine atoms act as acceptors and create holes in the valence band of MoTe 2 , leading to p-type doping. The mechanism of p-type doping of mechanically exfoliated MoTe 2 by bromine vapors can be explained as that the 2H-MoTe 2 crystal samples are grown by chemical vapor transport using bromine gas as a transport agent and doping source. , Chemical vapor transport (CVT) is a method used to grow single crystals of materials by transporting the material in the form of a vapor through a temperature gradient to a cooler region, where it condenses and forms a crystal . In this method, a source material is heated to produce vapors, which are then transported to a cooler region where they condense and form a crystal.…”