THE THERMOELECTRIC PROPERTIES OF STRONGLY CORRELATED SYSTEMS

Open Access
Author:
Cai, Jianwei
Graduate Program:
Physics
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
October 03, 2008
Committee Members:
  • Gerald Dennis Mahan, Dissertation Advisor
  • Gerald Dennis Mahan, Committee Chair
  • Jainendra Jain, Committee Member
  • Jorge Osvaldo Sofo, Committee Member
  • John V Badding, Committee Member
  • Jayanth R Banavar, Committee Member
Keywords:
  • thermoelectric
  • electron correlation
  • transport properies
Abstract:
Strongly correlated systems are among the most interesting and complicated sys- tems in physics. Large Seebeck coe±cients are found in some of these systems, which highlight the possibility for thermoelectric applications. In this thesis, we study the thermoelectric properties of these strongly correlated systems with var- ious methods. We derived analytic formulas for the resistivity and Seebeck coe±cient of the pe- riodic Anderson model based on the dynamic mean ¯eld theory. These formulas were possible as the self energy of the single impurity Anderson model could be given by an analytic ansatz derived from experiments and numerical calculations instead of complicated numerical calculations. The results show good agreement with the experimental data of rare-earth compound in a restricted temperature range. These formulas help to understand the properties of periodic Anderson model. Based on the study of rare-earth compounds, we proposed a design for the ther- moelectric meta-material. This manmade material is made of quantum dots linked by conducting linkers. The quantum dots act as the rare-earth atoms with heavier mass. We set up a model similar to the periodic Anderson model for this new material. The new model was studied with the perturbation theory for energy bands. The dynamic mean ¯eld theory with numerical renormalization group as the impurity solver was used to study the transport properties. With these studies, we con¯rmed the improved thermoelectric properties of the designed material.