Electronic density of states derived from thermodynamic critical field curves for underdoped La2-xSrxCuO4+delta

Article

关键词: HIGH-TC SUPERCONDUCTORS;    REVERSIBLE MAGNETIZATION;    II SUPERCONDUCTORS;    TEMPERATURE;    TRANSITION;    PSEUDOGAP;    MODEL;   

DOI  :  10.1103/PhysRevB.65.024523

来源: SCIE

【 摘 要 】

Thermodynamic critical field curves have been measured for La2-xSrxCuO4+delta over the full range of carrier concentrations where superconductivity occurs in order to determine changes in the normal-state density of states with carrier concentration. There is a substantial window in the H-T plane where measurements are possible because the samples are both thermodynamically reversible and the temperature is low enough that vortex fluctuations are not important. In this window, the data fit the Hao-Clem model rather well, so this model is used to determine H-c and kappa(c) for each temperature and carrier concentration. Using N(0) and the ratio of the energy gap to transition temperature, Delta(0)/k(B)T(c), as fitting parameters, the H-c vs T curves give Delta(0,)/k(B)T(c)similar to2.0 over the whole range of x. Values of N(0) remain rather constant in the optimum-doped and overdoped regime, but drop quickly toward zero in the underdoped regime.

【 授权许可】

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