  In two dimensions, an s-wave superconductor in the presence of Rashba
spin-orbit coupling possesses distinct topologically non-trivial ground state
phases controlled by Zeeman splitting and band filling. These phases can be
characterized in terms of spin textures in momentum space. Although the spin
texture becomes topologically trivial at finite temperatures, we identify
thermodynamic signatures that are directly related to the topological phase
transitions of the ground state. In particular, relative maxima in the entropy
as a function of the magnetic field in the vicinity of topological phase
transitions emerge and are attributed to a sign change in the derivative of the
magnetization with respect to temperature.
