The mission of this AoE is to set up an inter-disciplinary research platform that will generate fundamental knowledge and innovation in the field of wave functional materials. More specifically, we design, fabricate and characterize new materials that can manipulate light and sound in ways not known before.
We develop new and improve existing techniques for the realization of these new materials. We then use these wave functional materials to achieve interesting and unusual effects that are not possible with natural materials and we explore and realize potential applications of these new materials.
Please click here to read the news release of this AoE project.
Topological control of light and sound waves are completely new phenomena. Upper Panel shows topological one-way edge state on an acoustic topological phononic crystal. Metamaterials can have optical properties not found in nature. The bottom panel shows a metamaterial with index ellipsoids not centered about zero momentum.
Metamaterials can be used to study non-abelian gauge field. The following figure shows the research work, published in Nature, in experimentally observing a non-abelian topological charge using a time-reversal and inversion-symmetric transmission line network. The topological charge is quaternion-valued. Each red, green and blue arrow represents multiplication quaternion element +i, +j and +k, respectively, in extending algebra of complex numbers.
Selected Publications:
1. Wang, D., Yang, B., Guo, Q., Zhang, R.Y., Xia, L., Su, X., Chen, W.J., Han, J., Zhang, S. and Chan, C.T., 2021. Intrinsic in-plane nodal chain and generalized quaternion charge protected nodal link in photonics. Light: Science & Applications 10(1), pp.1-9.
2. Wang, M., Tang, L., Ng, C.Y., Messina, R., Guizal, B., Crosse, J.A., Antezza, M., Chan, C.T. and Chan, H.B., 2021. Strong geometry dependence of the Casimir force between interpenetrated rectangular gratings. Nature Communications 12(1), pp.1-9.
3. Li, X., Liu, Y., Lin, Z., Ng, J. and Chan, C.T., 2021. Non-Hermitian physics for optical manipulation uncovers inherent instability of large clusters. Nature Communications 12(1), pp.1-9.
4. Guo, Q., Jiang, T., Zhang, R.Y., Zhang, L., Zhang, Z.Q., Yang, B., Zhang, S. and Chan, C.T., 2021. Experimental observation of non-Abelian topological charges and edge states. Nature 594(7862), pp.195-200.
5. Jiang, T., Fang, A., Zhang, Z.Q. and Chan, C.T., 2021. Anomalous Anderson localization behavior in gain-loss balanced non-Hermitian systems. Nanophotonics 10(1), pp.443-452.
6. Tang, W., Jiang, X., Ding, K., Xiao, Y.X., Zhang, Z.Q., Chan, C.T. and Ma, G., 2020. Exceptional nexus with a hybrid topological invariant. Science 370(6520), pp.1077-1080.
7. Xiong, Z., Zhang, R.Y., Yu, R., Chan, C.T. and Chen, Y., 2020. Hidden-symmetry-enforced nexus points of nodal lines in layer-stacked dielectric photonic crystals. Light: Science & Applications 9, pp.176.
8. Cui, X.H., Ding, K., Dong, J.W and Chan, C.T., 2020. Realization of complex conjugate media using non-PT-symmetric photonic crystals. Nanophotonics 9(1), 195.
9. Wu, X., Li, X., Zhang, R.Y., Xiang, X., Tian, J., Huang, Y., Wang, S., Hou, B., Chan, C.T. and Wen, W., 2020. Deterministic scheme for two-dimensional type-II Dirac points and experimental realization in acoustics. Physical Review Letters 124(7), p.075501.
10. Zhao, D., Wang, Y.T., Fung, K.H., Zhang, Z.Q. and Chan, C.T., 2020. Acoustic metamaterials with spinning components. Physical Review B 101(5), p.054107.
11. Zhong, F., Ding, K., Zhang, Y., Zhu, S., Chan, C.T. and Liu, H., 2020. Angle-resolved thermal emission spectroscopy characterization of non-Hermitian metacrystals. Physical Review Applied 13(1), p.014071.
12. Wang, D., Liu, C., Zhang, S. and Chan, C.T., 2020. Chaotic photon spheres in non-Euclidean billiard. Nanophotonics 9(10), pp.3367-3372.
13. Wang, Q., Ding, K., Liu, H., Zhu, S. and Chan, C.T., 2020. Exceptional cones in 4D parameter space. Optics Express 28(2), pp.1758-1770.
14. Leung, H.M., Gao, W., Zhang, R., Zhao, Q., Wang, X., Chan, C.T., Li, J. and Tam, W.Y., 2020. Exceptional point-based plasmonic metasurfaces for vortex beam generation. Optics Express 28(1), pp.503-510.
15. Shi, Y., Zhu, T., Nguyen, K.T., Zhang, Y., Xiong, S., Yap, P.H., Ser, W., Wang, S., Qiu, C.W., Chan, C.T. and Liu, A.Q., 2020. Optofluidic microengine in a dynamic flow environment via self-induced back-action. ACS Photonics 7(6), pp.1500-1507.
16. Zhang, R.R., Zhao, Q.L., Wang, X., Li, J. and Tam. W.Y., 2020. Circular phase-dichroism of chiral metasurface using birefringent interference. Nano Letters 20, 2681.
17. Guan, D.S., Charlaix, E. and Tong, P., 2020. State and rate dependent contact line dynamics over an aging soft surface. Physical Review Letters 124, 188003.
18. Xiang, X., Wu, X.X., Li, X., Wu, P., He, H, Mu, Q.J., Wang, S.X., Huang, Y.Z. and Wen, W.J., 2020. Ultra-open ventilated metamaterial absorbers for sound-silencing applications in environment with free air flows. Extreme Mechanics Letters 39, 100786.
19. Han, Y., Ng, W.K., Xue, Y., Wong, K.S. and Lau, K.M., 2019. Room temperature III–V nanolasers with distributed Bragg reflectors epitaxially grown on (001) silicon-on-insulators. Photonics Research 7, 1081.
20. Han, Y., Yan, Z., Ng, W.K., Xue, Y., Wong, K.S. and Lau, K.M., 2020. Bufferless 1.5 μm III-V lasers grown on Si-photonics 220 nm silicon-on-insulator platforms. Optica 7, 148.
21. Wang, H., Chan, C.S., Chu, M., Xie, J.S., Zhao, S.H., Guo, X.L., Miao, Q., Wong, K.S., Yan, K.Y. and Xu, J.B., 2020. Interlayer cross-linked 2D perovskite solar cell with uniform phase distribution and increased exciton coupling. Solar RRL, 1900578.
22. Chai, G., Chang, Y., Peng, Z.X., Jia, Y.Y., Zou, X.H., Yu, D., Yu, H., Chen, Y.Z., Chow, C.Y., Wong, K.S., Zhang, J.Q., Ade., H., Yang, L.W. and Zhan, C.L., 2020. Enhanced hindrance from phenyl outer side chains on nonfullerene acceptor enables unprecedented simultaneous enhancement in organic solar cell performances with 16.7% efficiency. Nano Energy 76, 105087.
23. Chang, Y., Lau, T.K., Chow, C.Y., Wu, N.N., Su, D., Zhang, W.C., Meng, H.F., Ma, C., Liu, T., Li, K., Zou, X.H., Wong, K.S., Lu, X.H., Yan, H. and Zhan, C.L., 2020. A 16.4% efficiency organic photovoltaic cell enabled using two donor polymers with their sidechains oriented differently by a ternary strategy. Journal of Material Chemistry A 8, 3676.
24. Ma, L.K., Chen, Y.Z., Chow, C.Y., Zhang, G.Y., Huang, J.C., Ma, C., Zhang, J.Q., Yin, H., Cheung, M.H., Wong, K.S., So, S.K. and Yan, H., 2020. High-efficiency indoor organic photovoltaics with a band-aligned interlayer. Joule 4, 1.
25. Niu, G.L., Zheng, X.L., Zhao, Z., Zhang, H.K., Wang, J.G., He, X.W., Chen, Y.C., Shi, X.J., Ma, C., Kwok, T.K., Lam, W.Y., Sung, H.Y., Williams, I.D., Wong, K.S., Wang, P.F. and Tang, B.Z. AIE-active functionalized acrylonitriles: structure tuning by simple reaction-condition variation, efficient red emission and two-photon bioimaging. Journal of American Chemical Society (accepted 2020).
26. Alam, P., Leung, L.C., Liu, J.K., Cheung, T.S., Zhang, X.P., He, Z.K., Kwok, T.K., Lam, W.Y., Sung, H.Y., Williams, I.D., Chan, C.S., Wong, K.S., Peng, Q. and Tang, B.Z., 2020. Two are better than one: a design principle for ultralong-persistent luminescence of pure organics. Advanced Materials 32, 2001026.
27. Li, Y.Y., Vashishtha, P., Zhou, Z.C., Li, Z., Shivarudraiah, S.B., Ma, C., Liu, J.K., Wong, K.S., Su, H.B. and Halpert, E., 2020. Room temperature synthesis of stable, printable Cs3Cu2X5 (X = I, Br/I, Br, Br/Cl, Cl) colloidal nanocrystals with near-unity quantum yield green emitters (X = Cl). Chemistry of Materials 32, 5515-5524.
28. Zheng, Z., Liu, H.X., Zhai, S.D., Zhang, H.K., Shan, G.G., Kwok, T.K., Ma, C., Sung, H.Y., Williams, I.D., Lam, W.Y., Wong, K.S., Hu, X.L. and Tang, B.Z., 2020. Highly efficient singlet oxygen generation, two-photon photodynamic therapy and melanoma ablation by rationally designed mitochondria-specific near-infrared AIEgens. Chemical Science 11, 2494.
29. Burkhartsmeyer, J., Wang, Y.H., Wong, K.S. and Gordon, R., 2020. Optical trapping, sizing, and probing acoustic modes of a small virus. Applied Sciences 10, 394.
30. Ng, W.K., Han, Y., Lau, K.M. and Wong, K.S., 2019. Broadband telecom emission from InP/InGaAs nano-ridge lasers on silicon-on-insulator substrate. OSA Continuum 11, 3037.
31. Alam, P., He, W., Leung, L.C., Ma, C., Kwok, T.K., Lam, W.Y., Sung, H.Y., Williams, I.D., Wong, K.S. and Tang, B.Z., 2020. Red AIE-active fluorescent probes with tunable organelle-specific targeting. Advanced Functional Materials 30, 1909268.
32. Tang, S.T., Lau, J., Au Yeung, K.Y. and Yang, Z.Y., 2020. Multiple-frequency perfect absorption by hybrid membrane resonators. Applied Physics Letters 116, 161902.
33. Au-Yeung, K.Y., Yang, B., Sun, L., Bai, K.H. and Yang, Z.Y., 2019. Super damping of mechanical vibrations. Scientific Reports 9, 17793.
34. Qu, S.C. and Sheng, P., 2020. Minimizing indoor sound energy with tunable metamaterial surfaces. Physical Review Applied 14, 034060.
35. Yu, Y.Z., Kuo, C.Y., Chern, R.L. and Chan, C.T., 2019. Photonic topological semimetals in bianisotropic metamaterials. Scientific Reports, 9(1), pp.1-13.
36. Antezza, M., Chan, H.B., Guizal, B., Marachevsky, V.N., Messina, R. and Wang, M., 2020. Giant Casimir torque between rotated gratings and the θ= 0 anomaly. Physical review letters, 124(1), p.013903.
37. Zhang, X.L., Jiang, T. and Chan, C.T., 2019. Dynamically encircling an exceptional point in anti-parity-time symmetric systems: asymmetric mode switching for symmetry-broken modes. Light: Science & Applications 8(1), pp.1-9.
38. Guo, Q., You, O., Yang, B., Sellman, J.B., Blythe, E., Liu, H., Xiang, Y., Li, J., Fan, D., Chen, J. and Chan, C.T., 2019. Observation of three-dimensional photonic dirac points and spin-polarized surface arcs. Physical Review Letters 122(20), p.203903.
39. Wang, S., Hou, B., Lu, W., Chen, Y., Zhang, Z.Q. and Chan, C.T., 2019. Arbitrary order exceptional point induced by photonic spin–orbit interaction in coupled resonators. Nature Communications 10(1), pp.1-9.
40. Ding, K., Ma, G., Zhang, Z.Q. and Chan, C.T., 2018. Experimental demonstration of an anisotropic exceptional point. Physical Review Letters 121(8), p.085702.
41. Zhang, X.L., Wang, S., Hou, B. and Chan, C.T., 2018. Dynamically encircling exceptional points: in situ control of encircling loops and the role of the starting point. Physical Review X 8(2), p.021066.
42. Wang, S., Ma, G. and Chan, C.T., 2018. Topological transport of sound mediated by spin-redirection geometric phase. Science Advances 4(2), p.eaaq1475.
43. Wang, Q., Xiao, M., Liu, H., Zhu, S. and Chan, C.T., 2017. Optical interface states protected by synthetic Weyl points. Physical Review X 7(3), p.031032.
44. Xiao, Y.X., Ma, G., Zhang, Z.Q. and Chan, C.T., 2017. Topological subspace-induced bound state in the continuum. Physical review letters, 118(16), p.166803.
45. Luo, J., Yang, Y., Yao, Z., Lu, W., Hou, B., Hang, Z.H., Chan, C.T. and Lai, Y., 2016. Ultratransparent media and transformation optics with shifted spatial dispersions. Physical Review Letters 117(22), p.223901.
46. Chen, W.J., Xiao, M. and Chan, C.T., 2016. Photonic crystals possessing multiple Weyl points and the experimental observation of robust surface states. Nature Communications 7(1), pp.1-10.
47. Ding, K., Ma, G., Xiao, M., Zhang, Z.Q. and Chan, C.T., 2016. Emergence, coalescence, and topological properties of multiple exceptional points and their experimental realization. Physical Review X 6(2), p.021007.
48. Xiao, M., Chen, W.J., He, W.Y. and Chan, C.T., 2015. Synthetic gauge flux and Weyl points in acoustic systems. Nature Physics 11(11), pp.920-924.
49. Xiao, M., Ma, G., Yang, Z., Sheng, P., Zhang, Z.Q. and Chan, C.T., 2015. Geometric phase and band inversion in periodic acoustic systems. Nature Physics 11(3), pp.240-244.
50. Chen, W.J., Jiang, S.J., Chen, X.D., Zhu, B., Zhou, L., Dong, J.W. and Chan, C.T., 2014. Experimental realization of photonic topological insulator in a uniaxial metacrystal waveguide. Nature Communications 5(1), pp.1-7.
51. Xiao, M., Zhang, Z.Q. and Chan, C.T., 2014. Surface impedance and bulk band geometric phases in one-dimensional systems. Physical Review X 4(2), p.021017.
52. Wang, S.B. and Chan, C.T., 2014. Lateral optical force on chiral particles near a surface. Nature Communications 5(1), pp.1-8.
Ice surfaces have a thin layer of water below its melting temperature of 0℃. Such premelting phenomenon is important for skating and snowflake growth. Similarly, liquid often crystallizes into a thin layer of crystal on a flat substrate before reaching its freezing temperature, i.e. prefreezing. The thickness of the surface layer usually increases and diverges as approaching the phase transition (such as melting and freezing) temperature. Besides premelting and prefreezing, whether similar surface phenomenon exists as a precursor of a phase transition has rarely been explored.
Researchers at the HKUST and the University of Chicago (UChicago) have shown for the first time how to design the basic elements needed for logic operations using a kind of soft material called liquid crystal, paving the way for a completely novel way of performing computations with potential applications in robotics.