Abstract:

The well-known three modes of heat transfer, including conduction, convection, and radiation, pave the way of flexibly controlling thermal distributions by varied implementations, thus further contributing to the emerging thermal time-varying metamaterials. In this talk, we will introduce new developments of hybrid thermal materials with artificial meta-structures to realize extremely high effective thermal conduction. We will also introduce our more recent breakthrough in topological thermal materials by constructing an orthogonal convective space with two pairs of counter-motion convections for encircling exceptional points (EPs). Configurable phase transitions were subsequently demonstrated by adjusting the EP quantities in the orthogonal convective space. Further, we report the realization of Weyl exceptional ring in thermal diffusion by using two pairs of spatiotemporal advections to obtain three imitated dimensions. The spatiotemporal thermal coupling can give rise to diffusive Fizeau drag, which features different speeds of temperature field propagation in opposite directions. We further tailor the modulated Hermiticity in both space and time, and establish an advective paradigm by periodically stacked fluid surfaces. Topological edge and conventional bulk states, as well as interface states and topological manipulations, are revealed in thermal diffusion for the first time. Those works pave the foundation of the area of topological thermal metamaterials.

References:

Y. Li, K.-J. Zhu, Y.-G. Peng, W. Li, T. Yang, H.-X. Xu, H. Chen, X.-F. Zhu, S. Fan, C.-W. Qiu, “Thermal meta-device in analogue of zero-index photonics”, Nature Materials 18, 48-54 (2019).

Y. Li, Y.-G. Peng, L. Han, M.-A. Miri, W. Li, M. Xiao, X.-F. Zhu, J. Zhao, A. Alu, S. Fan, C.-W. Qiu, “Anti-parity-time symmetry in diffusive systems”, Science 364, 170-173 (2019).

Y. Li, W. Li, T. Han, X. Zheng, J. Li, B. Li, S. Fan, and C.-W. Qiu, “Transforming heat transfer with thermal metamaterials and devices”, Nature Reviews Materials 6, 488 (2021).

 G. Xu, Y. Li, W. Li, S. Fan, and C.-W. Qiu, “Configurable Phase Transitions in a Topological Thermal Material”, Physical Review Letters 127, 105901 (2021).

G. Xu, Y. Yang, X. Zhou, H. Chen, A. Alu, and C.-W. Qiu, "Diffusive Topological Transport in Spatiotemporal Thermal Lattices", Nature Physics 18, 450 (2022).

 M. Liu, S. Xia, W. Wan, J. Qin, H. Li, C. Zhao, L. Bi and C.-W. Qiu, “Broadband mid-infrared non-reciprocal absorption using magnetized gradient epsilon-near-zero thin films”, Nature Materials 22, 1196 (2023).

BIO

Cheng-Wei Qiu is Fellow of APS, Optica, SPIE and The Electromagnetics Academy, US. He is the recipient of President’s Science Award 2023, the highest science distinction in Singapore. He was elected Fellow of ASEAN Academy of Engineering and Technology. He is well known for his research in structured light and interfaces. He has published over 580 peer-reviewed journal papers. He was the recipient of URSI Young Scientist Award in 2008, NUS Young Investigator Award in 2011, MIT TR35@Singapore Award in 2012, Young Scientist Award by Singapore National Academy of Science in 2013, Faculty Young Research Award in NUS 2013, SPIE Rising Researcher Award 2018, Young Engineering Research Award 2018, and Engineering Researcher Award 2021 in NUS, and World Scientific Medal 2021 by Institute of Physics, Singapore, Achievement in Asia Award (Robert T. Poe Prize) by International Organization of Chinese Physicists and Astronomers in 2022. He was Highly Cited Researchers in 2019, 2020, 2021, 2022, 2023 by Web of Science. As an overseas partner, he has been awarded China’s Top 10 Optical Breakthroughs for 5 times (2019, 2020, 2021(one in Fundamental Research, and one in Applied Research), 2023). He has been serving in Associate Editor for various journals such as JOSA B, PhotoniX, Photonics Research, and Editor-in-Chief for eLight. He also serves in Editorial Advisory Board for Laser and Photonics Review, Advanced Optical Materials, and ACS Photonics