Superconducting condensation energy in the pseudogap region of La2−xSrxCuO4

Abstract

The superconducting condensation energy at T=0, U0, was examined from the measurements of the electronic specific heat Cel on La2−xSrxCuO4. We reconfirmed that U0 is markedly reduced in the pseudogap regime (x≲0.2). The doping-level (p) dependence of U0 as well as Tc can be explained in the pseudogap regime by introducing an effective energy gap Δeff=βpΔ0 (β=4.5) instead of the maximum gap Δ0 at T≪Tc.