Abstract
Abstract Cherenkov radiation in natural transparent materials is generally forward-propagating, owing to the positive group index of radiation modes. While negative-index metamaterials enable reversed Cherenkov radiation, the forward photon emission from a swift charged particle is prohibited. In this work, we theoretically investigate emission behaviours of a swift charged particle in the nanometallic layered structure. Our results show that Cherenkov photons are significantly enhanced by longitudinal plasmon modes resulting from the spatial nonlocality in metamaterials. More importantly, longitudinal Cherenkov photons can be directed either forward or backward, stringently depending on the particle velocity. The enhanced flexibility to route Cherenkov photons holds promise for many practical applications of Cherenkov radiation, such as novel free-electron radiation sources and new types of Cherenkov detectors.
Highlights
Cherenkov radiation refers to the physical effect that a charged particle with a velocity exceeding the phase velocity of light in a medium can emit coherent photons at a constant angle [1, 2]
Our results show that Cherenkov photons are significantly enhanced by longitudinal plasmon modes resulting from the spatial nonlocality in metamaterials
We theoretically demonstrate that the spatial nonlocality in metamaterials provides a new degree of freedom to direct Cherenkov photons
Summary
Cherenkov radiation refers to the physical effect that a charged particle with a velocity exceeding the phase velocity of light in a medium can emit coherent photons at a constant angle [1, 2]. Cherenkov radiation in natural transparent materials is generally forward-propagating, because of the positive group velocity of radiation modes. To overcome this problem, researchers come up with numerous negative-index metamaterials to manipulate Cherenkov radiation [13,14,15,16,17,18]. H. Hu et al.: Cherenkov photons the sign of effective group index of longitudinal modes is dependent on the particle velocity in the nonlocal layered structure. The variation of particle velocity enables us to route longitudinal Cherenkov photons in backwardpropagating direction or forward-propagating direction at will
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
