Anomal behavior of tellurium under pressure

Elemental tellurium is a small bad-gap semiconductor with a unique chiral crystal structure and a spin texture of the valence bands, which allows in-parallel current-induced magnetization of p-doped samples. Under pressure the band gap narrows and the structure of the valence band changes from a narrow camel-back close to the H-point to a single maximum with radial spin texture. Here. we present a theoretical and experimental study of the low-temperature behavior of the chemically extremely pure, but doped by vacancies, tellurium under pressure. We identify an anomaly at low temperatures, which is related to the orbital structure of the vacancy states and the respective spin texture. The pressure induced change of the valence band leads to the emergence of a change of the orbital structure of the vacancies, effectively leading to an exotic quantum critical point. At one side of the transition strong weak antilocalization is observed, which is consistent with our DFT-calculations, which show a change in spin texture.