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Ⅰ: Atomic-scale Magneto-chiral Effect
The interplay between chirality and magnetism generates a distinct physical process, the magneto-chiral effect, which enables one to develop functionalities that cannot be achieved solely by any of the two. Such a process is universal with the breaking of parity-inversion and time-reversal symmetry simultaneously. However, the magneto-chiral effect observed so far is weak when the matter responds to photons, electrons, or phonons. Here we report the first observation of strong magneto-chiral response to excitons in a twisted bilayer tungsten disulfide with the amplitude of excitonic magneto-chiral anisotropy reaches a value of ~4%.
Ⅱ: On-chip Monolithic Full-Stokes Polarimeter
The ability to detect the full-Stokes polarization of light is vital for a variety of applications that often require complex and bulky optical systems. Here, we report an on-chip polarimeter comprising four metasurface-integrated graphene–silicon photodetectors. The geometric chirality and anisotropy of the metasurfaces result in circular and linear polarization-resolved photoresponses, from which the full-Stokes parameters, including the intensity, orientation, and ellipticity of arbitrarily polarized incident infrared light (1550 nm), can be obtained. The design presents an ultracompact architecture while excluding the standard bulky optical components and structural redundancy.
Ⅲ: Augmented Reality on Contact Lenses
Augmented reality (AR) has the potential to revolutionize the way in which information is presented by overlaying virtual information onto a person’s direct view of their real-time surroundings. By placing the display on the surface of the eye, a contact lens display (CLD) provides a versatile solution for compact AR. However, an unaided human eye cannot visualize patterns on the CLD simply because of the limited accommodation of the eye. Here, we introduce a holographic display technology that casts virtual information directly to the retina so that the eye sees it while maintaining the visualization of the real world intact.
Ⅳ: Plasmonic Bound States in the Continuum
Due to the unique ability of nanostructured metals to confine and enhance light waves along with metal-dielectric interfaces, plasmonics has enabled unprecedented flexibility in manipulating light at the deep-subwavelength scale. To the spectral behavior of plasmonic resonances, the spectral location of resonance can be tailored with relative ease, while the control over the spectral linewidth represents a more daunting task. In this paper, we present sharp resonance features by introducing dark plasmonic modes in diatomic gratings. The induced asymmetry in the metallic structure supports dark modes, also called bound states in the continuum.
Sep 2021: Our paper on high-harmonic vortex generation is in Advanced Optical Materials. Excellent collaboration with Drs. Kang and Werner.
Aug 2021: Dr. Lan gave an invited talk on chirality and magnetism at the 5th Symposium on 2D and Other Low-Dimensional Materials. Thank you, Drs. Cheng Gong and Kevin Daniels, for the invitation and organizing the conference.
Apr 2021: Our third Nature Communications paper is online, working on the magneto-chiral effect at the atomic scale (news released). The magneto-chiral effect can induce asymmetric synthesis, and arguably it also accounts for the homochirality of all living organisms on the earth.
Nov 2020: In collaboration with Drs. Xiaomu Wang, Yang Xu, Douglas H. Werner, Lei Kang, and Mark L. Brongersma, our paper on a monolithic full-Stokes polarimeter is online in ACS Nano. Congrats!