Many experiments reveal that in iron-based superconductors the jump of the specific heat ΔC at the superconducting Tc is not proportional to Tc, as expected in BCS theory. Rather, ΔC/Tc varies with Tc, and has a peak near optimal doping and decreases at smaller and larger dopings. We show that this behavior can be naturally explained by the interplay between superconductivity and antiferromagnetism. We demonstrate on general grounds that ΔC/Tc peaks at the doping where the coexistence phase with antiferromagnetism develops, and decreases at deviations from this doping in both directions. Our results are in quantitative agreement with the experiments.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Oct 7 2011|