Simulating Thermopower in Mott-Hubbard Materials

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project will use ultra-cold atoms trapped in an optical lattice to explore thermopower in the Hubbard model. Thermoelectric (TE) materials will play a key role in near- and long-term reliable methods for efficient power generation and cooling in a wide variety of applications. Material properties such as thermopower and total thermal conductivity presently limit the efficiency of TE power generation and cooling. The next revolution in TE power generation is therefore likely to come from fundamentally new materials having increased thermopower. Extraordinary thermopower has been observed in Mott-Hubbard (MH) systems, which are the same materials that give rise to high-temperature superconductivity. Unfortunately, no complete, predictive theory for thermopower in MH systems exists, and optimizing these materials for TE applications is therefore a daunting challenge. Ultra-cold 40K atoms trapped in an optical lattice will be used to simulate thermopower in the Hubbard model, which is the paradigm for MH materials. Techniques will be developed to enable measurements of the impact of material parameters, temperature, doping, and nanoscale morphology on thermopower. These studies will be used to advance understanding of thermopower in the MH systems through comparisons with theory and experiments on materials Transferring knowledge gained using this system to the design of new materials may enable more efficient vehicles requiring less fuel, refrigeration competitive with conventional technology, and lighter nuclear payloads for RTGs. The next generation of engineers and scientists will be trained on cutting edge technologies in laser science; high frequency microwave electronics; and high speed, computer-controlled signaling. Students will also be engaged in developing the emerging interface between condensed matter and atomic physics.