Geometric characterization of thermoelectric performance of two-dimensional quadratic band-crossing semimetals
2024.03.27 10:14
| 날짜 | 2024-03-28 11:00 |
|---|---|
| 연사 | Chang-geun Oh(PhD candidate, The University of Tokyo) |
| 장소 | E6, #2501 |
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Date: 11:00 Am, 28th Mar (Thu.)
Place: E6, #2501
Speaker: Chang-geun Oh(PhD candidate, The University of Tokyo)
Title: Geometric characterization of thermoelectric performance of two-dimensional quadratic band-crossing semimetals
Abstract:
The geometric characteristics of Bloch wave functions play a crucial role in electronic transport properties. We show that the thermoelectric performance of materials is enhanced by the geometric structure of electronic wavefunctions within the framework of the Boltzmann equation. The essential geometric notion is the HilbertSchmidt quantum distance, measuring the resemblance between two quantum states. The geometric characterization of the scattering rate is established by extending the concept of quantum distance between two states at distance in the base manifold. Employing isotropic quadratic band touching models for which we can concentrate on the role of quantum metric tensor, we reveal that the response functions for electrical quantum transport and therefore the thermoelectric power factor can be succinctly expressed in terms of the maximum quantum distance, dmax. Specifically, when dmax reaches one, the power factor doubles compared to the case with trivial geometry (dmax = 0). Our finding highlights the significance of the quantum geometry in improving the performance of thermoelectric devices and providing the practical usages of topological material.
