Time: 03:00 CET, 26th February, 2023

Zoom link:  https://unsw.zoom.us/j/86793035860

Chairmain: Asst. Prof. Hoang-Phuong Phan

​

You are most welcome to a knowledge-sharing seminar presented by Asst. Prof. Nguyen Tuan Hung at Tohoku University. With a friendly atmosphere, you will have a great chance to discuss and communicate with this young scientist for any potential collaborations or research experience.

​

Title:

Thermoelectricity in quantum material:

From low-dimensional to topological materials

 

Abstract: 

Entangling heat and charge in the material can help to convert waste heat to electricity, so-called thermoelectricity that provides an ideal supply for the Internet of things (IoT) sensors. Finding the thermoelectric (TE) material with high-performance energy conversion is the most important goal in this field. However, it is not easy because of the interdependence of the TE transport parameters (i.e. Seebeck coefficient, electrical conductivity, and thermal conductivity). In order to solve this fundamental problem, attempts started for the thermoelectricity of low-dimensional materials in 1993 when Hicks and Dresselhaus presented the quantum confinement effect [1]. This effect is based on the fact that the density of states has sharp peaks (or so-called van Hove singularity) at the energy edges of the dimensional materials [2, 3]. The van Hove singularity also can occur in other quantum materials, such as the atomic layers and topological materials, due to their unique energy band structure. On the other hand, the emergent 3D quantum semimetals show many features (high carrier mobility, low thermal conductivity, etc.) that could be beneficial to improve TE properties [4]. In this talk, first, we show how low-dimensional materials improve TE performance. In particular, we will discuss the high TE performance of the monolayer InSe [5] and tetradymites [6]. Second, we will discuss the TE properties of the 3D Dirac/Weyl/Nodal-line semimetals with non-trivial band topology by the semi-analytical calculation with the two-band model and the first-principles calculations [7, 8].

​

Biography:

Nguyen Tuan Hung is an assistant professor at the Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Japan. He received a Ph.D. in Physics and Interdepartmental Doctoral Degree Program from Tohoku University in March 2019 with a shortened period. He was awarded the Aoba Society Prize for the Promotion of Science from Tohoku University in 2017, Research Fellowships for Young Scientists from Japan Society for the Promotion of Science (JSPS) in 2018, and Tohoku University Prominent Research Fellow in 2021. He was visiting scholar at Chinese Academy of Sciences, China, and MIT, USA. His research interests are in the theory and simulation of energy materials with applications to thermoelectricity, all-solid-state batteries, photovoltaics, and artificial muscles. He also was the first author of the textbook “Quantum ESPRESSO Course for Solid-State Physics”, Jenny Stanford Publishing, 2022.

References

[1] L. D. Hicks, M. S. Dresselhaus, Phys. Rev. B 47, 12727 (1993); Phys. Rev. B 47, 16631 (1993).

[2] N. T. Hung, E. H. Hasdeo, A. R. T. Nugraha, M. S. Dresselhaus and R. Saito, Phys. Rev. Lett. 117, 036602 (2016).

[3] N. T. Hung, R. Saito, Adv. Quantum Technol. 4, 2000115 (2021).

[4] B. Skinner and L. Fu, Sci. Adv. 4, eaat2621 (2018).

[5] N. T. Hung, A. R. T. Nugraha and R. Saito, Appl. Phys. Lett. 111, 092107 (2017).

[6] N. T. Hung, A. R. T. Nugraha, R. Saito, Nano Energy 58, 743 (2019).

[7] N. T. Hung, A. R. T. Nugraha, J. M. Adhidewata, and R. Saito, Phys. Rev. B 105, 115142‑1‑5 (2022).

[8] P. R. Pratama, R. Saito, and N. T. Hung, Phys. Rev. B (Letter) 106, L081304 (2022).

​