  The iron-based superconductor FeSe offers a unique possibility to study the
interplay of superconductivity with purely nematic as well magnetic-nematic
order by pressure (p) tuning. By measuring specific heat under p up to 2.36GPa,
we study the multiple phases in FeSe using a thermodynamic probe. We conclude
that superconductivity is bulk across the entire p range and competes with
magnetism. Our analysis suggests that superconducting and magnetic fluctuations
exist over a wide temperature range above the respective bulk transition
temperatures, whenever magnetism is present. These observations highlight
similarities between FeSe and underdoped cuprate superconductors where
fluctuations play a crucial role.
