We present a study of the Nernst effect in amorphous 2D superconductor
InOxβ, whose low carrier density implies low phase rigidity and strong
superconducting phase fluctuations. Instead of presenting the abrupt jump
expected at a BCS transition, the Nernst signal evolves continuously through
the superconducting transition as previously observed in underdoped cuprates.
This contrasts with the case of Nb0.15βSi0.85β, where the Nernst signal
due to vortices below Tcβ and by Gaussian fluctuations above are clearly
distinct. The behavior of the ghost critical field in InOxβ points to a
correlation length which does not diverge at Tcβ, a temperature below which
the amplitude fluctuations freeze, but phase fluctuations survive.Comment: 4 pages, 4 figure