Implications of fluctuation effects on thermodynamic quantities in type II superconductors

It is pointed out that the lowest Landau level (LLL) approach is not valid at all for magnetization above Hc2 in high Tc superconductors (HTSC) under several tesla, although fluctuation-induced scaling behavior is often observed, and that inclusion of higher LL fluctuations is indispensable in understanding such behavior of the magnetization. In contrast, the scaling behavior is found in heat capacity data primarily below Hc2 and can be understood within the LLL approach. The temperature dependence of the magnetization below Hc2 will also be commented. (orig.)