| We studied the transport properties such as the Hall effect and Nernst effect of several high Tc superconductors (HTS) and the magnetic effect on the transport properties of the quisi-one dimensional conductor NbSe3. The former study provides better comprehension of the physics of the pseudogap state, and the latter promotes the knowledge on charge-density wave (CDW) in low-dimensional materials.The low carriers concentration and short coherence length in HTSs lead to the strong electron-electron correlation and strong magnetic coupling, which causes many anomalous phenomena in HTSs, especially in the normal state. The BCS theory, which was verified correct in the conventional superconductors, now is challenged. A pseudogap (PG) opens in the normal state far above the critical temperature Tc. The PG is anisotropic, having the same symmetry as the superconduting gap. So the question is raised now:What is the relationship between superconducting gap and pseudogap? What is the mechanism of Cooper pairs formation? What is the electronic state before and after Cooper pairs condense? The mechanism of HTSs is one of the hottest issues in the feld of Condensed Matter Physics nowadays and the relationship between pseudogap and superconductivity is very crucial to the mechanism.Nernst signal is very sensitive to the motion of vortex, and therefore the Nernst effect becomes an important probe to detect whether the vortex-like excitation exist or not in the pseudogap region. In this thesis, based on the Nernst effect and other eletronic and thermal transport properties, we performed a systemic study on the transport properties of overdoped Bi2Sr2CaCu2O8+y (Bi-2212) single crystals and Zn doped YBa2(Cu1-xZnx)3O7-δepitaxial thin films. The study of Bi-2212 clarifies the evolution of T* (temperature where the pseudogap opens) in the overdoped region and the superconducting fluctuation behavior. We derived various characteristic temperatures from various experiments and renewed the phase diagram of overdoped region finally. From the measurements of Zn doped YBCO, we found the Nernst signal decreases dramatically with the Zn doping, and the characteristic temperature Tv where the vortex Nernst signal disappears decreases as Tc0 does. We interpreted the results within the scenario that Zn doping causes a sharp decrease in the superfluid density and therefore suppresses the superconductivity. Finally, we discussed the different behavior of various characteristic temperatures with Zinc doping. All these studies show that there exists strong superconducting phase fluctuation in finite temperature region above Tc0. Our results also imply that there are two different regimes in the PG state. At the temperature from Tc0 to Tv the superconducting phase fluctuation is dominate, and in the temperature region from Tv to T*, the phase correlation between Cooper pairs disappears completely and only finite amplitude fluctuation of superconducting order parameter remains.In the last chapter of this thesis, we investigated the temperature and magnetic field dependence of resistivity and thermopower of CDW conductor NbSe3. We found that, in the lower CDW state (T |
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