Fig. 1: Electronic properties of Br-doped 2H-MoTe₂.

a Crystal structure of 2H-MoTe₂ where we indicate the basis vectors \(\overrightarrow{a}\),\(\overrightarrow{b}\),\(\overrightarrow{c}\) of the Bravais lattice. The Mo atoms are in purple, the Te atoms in yellow. The horizontal mirror plane σ_h is indicated as a dashed line. b Brillouin zone where we indicate the basis vectors \({\overrightarrow{a}}^{\star }\),\({\overrightarrow{b}}^{\star }\) of the reciprocal lattice and the points of high symmetry. The star of wavevectors Q and \(\bar{{{{{{{{\bf{Q}}}}}}}}}\) are indicated as red and blue arrows, respectively. c Angular resolved photoemission (ARPES) map in the Γ-K direction measured at T = 12 K. The continuous lines indicate the contours of the conduction bands (Q_3,4, K_9,10,11,12) and valence bands (K_7,8) extrema obtained from density functional theory (DFT) calculations⁶⁷. The bands are labeled according to the irreps of the corresponding groups of wavevectors^27,28. The two colors, red and blue, indicate bands of opposite spin polarization. Note how the valleys of opposite momentum have opposite spin polarization. The Q-valleys are not visible in the ARPES data because of the low carrier density, however, the position of the Fermi level, indicated as an horizontal dashed line, 1 eV above the valence band, indicates the presence of the carriers in those Q-valleys. The band-gap E_BG ≈ 1 eV and the spin-orbit induced splitting Δ_SO ≈ 250 meV are indicated. d Arrhenius plot of resistivity (orange line), electron spin resonance (ESR) spin coherence lifetime T\({}_{2}^{* }\) (blue dot line) and hopping correlation time τ_c (blue continuous line) as function of temperature. The different transport regimes are identified by the colored panels: blue for the saturation regime, pink for the activated regime and green for the variable range hopping (VRH) regime. The dashed lines, displaced for clarity, are fits of the resistivity with the activated law and Mott law. e ESR signal as function of temperature, from 30 K (red) down to 8 K (blue), measured with the magnetic field perpendicular to the c-axis, from which a g-factor g ≈ 2.018 is obtained. The ESR line is observed only below T ≈ 25 K, in the VRH regime. The spin coherence time T\({}_{2}^{* }\) extracted from the ESR linewidth is shown panel d. f ESR signal measured for a magnetic field perpendicular (blue) and parallel (orange) to \(\overrightarrow{c}\), from which the g-factor anisotropy is obtained. The dashed lines are fitted to the data using an effective spin Hamiltonian, see Supplementary Note 2.