Many experiments during the previous decade registered spin-triplet superconductivity in doped Bi2Se3. This superconductivity breaks C3 rotational symmetry in the (ГM; ГK) plane. Only one possible order parameter with vector structure satisfies these properties. This order parameter is called nematic due to it demonstrates C2 rotational symmetry.

We calculated critical temperature for different superconducting phases and showed that hexagonal warping of the Fermi surface stabilizes this nematic order parameter compared with other superconducting order parameters.

Further, we theoretically investigate quasiparticle interference on the surface of a nematic superconductor. We classified the main scattering features and compared them with the experimental results in the Bi2Te3\FeTeSe heterostructure.

We analyze nematic superconductors in the Zeeman field in the Ginzburg-Landau approach. We calculated GL coefficients from microscopic theory. Due to the spin-triplet nature of the order parameter and its coupling with the Zeeman field, the paramagnetic response of the Cooper pair's spin was found.