Metasurface is a kind of two-dimensional metamaterial with specially designed sub-wavelength unit cells.It consists of single-layer or few-layer stacks of planar structures and possesses certain superior abilities to ...Metasurface is a kind of two-dimensional metamaterial with specially designed sub-wavelength unit cells.It consists of single-layer or few-layer stacks of planar structures and possesses certain superior abilities to manipulate the propagating electromagnetic waves,including the terahertz(THz)ones.Compared with the usual passive THz metasurfaces whose optical properties are difficult to be controlled after fabrication,the active materials are highly desirable to enable dynamic and tunable control of THz waves.In this review,we briefly summarize the progress of active THz metasurfaces,from their physical mechanisms on carrier concentration modulations,phase transitions,magneto-optical effects,etc.,for various possible THz applications mainly with low-dimensional materials,vanadium dioxide films,and superconductors.展开更多
Recently, with the precise laser interferometers the LIGO- Virgo collaboration [ 1-4] has realized the direct detection of the GWs, by probing their minute mechanical displacements. The peak strains of the detected GW...Recently, with the precise laser interferometers the LIGO- Virgo collaboration [ 1-4] has realized the direct detection of the GWs, by probing their minute mechanical displacements. The peak strains of the detected GWs are at the order of 10-21 and their frequencies are in the low- and intermediate frequency band, i.e., dozens and hundreds of Hertz. Given the GWs could exist at any frequency [5, 6], in principle, probing the GWs in the wider bands [7, 8], typically the high frequency GWs expected by a series of models for cosmology and high-energy astrophysical processes [9-12], is still a challenge [13].展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11974290)the Fundamental Research Funds for the Central Universities,China(Grant No.2232020D-44).
文摘Metasurface is a kind of two-dimensional metamaterial with specially designed sub-wavelength unit cells.It consists of single-layer or few-layer stacks of planar structures and possesses certain superior abilities to manipulate the propagating electromagnetic waves,including the terahertz(THz)ones.Compared with the usual passive THz metasurfaces whose optical properties are difficult to be controlled after fabrication,the active materials are highly desirable to enable dynamic and tunable control of THz waves.In this review,we briefly summarize the progress of active THz metasurfaces,from their physical mechanisms on carrier concentration modulations,phase transitions,magneto-optical effects,etc.,for various possible THz applications mainly with low-dimensional materials,vanadium dioxide films,and superconductors.
基金supported by the National Natural Science Foundation of China (Grant No. U1330201)
文摘Recently, with the precise laser interferometers the LIGO- Virgo collaboration [ 1-4] has realized the direct detection of the GWs, by probing their minute mechanical displacements. The peak strains of the detected GWs are at the order of 10-21 and their frequencies are in the low- and intermediate frequency band, i.e., dozens and hundreds of Hertz. Given the GWs could exist at any frequency [5, 6], in principle, probing the GWs in the wider bands [7, 8], typically the high frequency GWs expected by a series of models for cosmology and high-energy astrophysical processes [9-12], is still a challenge [13].
