Spin-orbital texture in quasi-one-dimensional giant rashba system on bi / inas ( 110 )-( 2 × 1 )

MAX phases (Mn+1AXn, where M is an early transition metal, A belongs to groups 13-15 and X is either C or N, n = 1 3) have recently attracted much attention due to their possible application to the production of a new class of two-dimensional (2D) systems called MXenes [1]. However, the bulk electronic structure of MAX phases has been studied mostly through ab initio, DFT calculations, mainly due to a lack of single crystalline samples. We have performed angle-resolved photoemission spectroscopy (ARPES) on several MAX phase single crystals to directly investigate the electronic structure of these systems [2,3]. Among the MAX phases, V2AlC has been expected to be categorized as a high-symmetry point semi-metal with crossing point with some Dirac-like properties referred as “Dirac point (DP)” at the Fermi level (EF) along ΓM line together with “nodal-line (NL)” around 0.2 eV from DFT calculation [3, 4]. To elucidate the electronic structure, especially, the existence of DP and spin-polarized states, we have performed spin and angle resolved ARPES (SARPES) with using a quasi continuous wave laser [5]. As a result, we have found the formation of the Dirac cone is consistent with DFT calculation (Fig.1). Furthermore, the SARPES clearly demonstrates spin-polarized branches (S+ and S-) in the larger electron pocket (eL), where the spin directions are opposite to each other and tangential to the Fermi surface along the ΓM line (Fig.2). Furthermore, missing of the out-of-plane spin polarization as well as inversion symmetry breaking at the observed