Jump in specific heat in the presence of a spin-density wave at the superconducting transition in iron pnictides

M. G. Vavilov, A. V. Chubukov, A. B. Vorontsov
2011 Physical Review B  
We analyze the magnitude of the specific heat jump \Delta C at the superconducting transition temperature T_c in the situation when superconductivity develops in the pre-existing antiferromagnetic phase. We show that \Delta C/T_c differs from the BCS value and is peaked at the tri-critical point where this coexistence phase first emerges. Deeper in the magnetic phase, the onset of coexistence, T_c, drops and \Delta C/T_c decreases, roughly as \Delta C/T_c \propto T^2_c at intermediate T_c and
more » ... ponentially at the lowest T_c, in agreement with the observed behavior of \Delta C/T_c in iron-based superconductors.
doi:10.1103/physrevb.84.140502 fatcat:tgxpbcau4jdcxmeoh7ic7cweoa