Nonreciprocal Nonmagnetic Thermal Photonics
Abstract
The objective of this YIP project is to develop a comprehensive research program dedicated to exploring, theoretically, computationa,lly, and experimentally, novel nonreciprocal nonmagnetic platforms for thermal photonics, with far-reaching implications for photoni,c thermal management and energy harvesting. Specifically, we plan to demonstrate, for the first time, a nonreciprocal nonmagnetic me,ta-surface platform with broken symmetry between light emission and absorption at infrared wavelengths. In conventional materials an,d systems, the emissivity of a material is exactly equal to its absorptivity according to Kirchhoffs law of thermal radiation. Rath,er remarkably, this law is not a consequence of the Second Law of Thermodynamics, but it originates directly from the reciprocity pr,inciple and is analogous to other relevant symmetries in electromagnetics, such as the fact that antennas can be used in reception a,nd transmission with exactly the same gain and directivity. Conventional approaches to break these symmetries involve using magneto-,optical materials and large external magnets, or more recently, dynamically modulated systems, which, however, are impractical and i,nefficient at optical frequencies. This YIP project will investigate and demonstrate, for the first time, a drastically novel method, to realize strong nonreciprocity in optical materials and systems without the need for magneto-optical or dynamical effects. Specif,ically, we will study an approach that relies on a form of drift-induced breaking of time-reversal symmetry in certain conducting,materials biased by a direct electric current. Initial theoretical and computational results confirm the feasibility of realizing st,rong and broadband nonreciprocity if the electron drift velocity is large enough to affect the dispersion of surface plasmon-polarit,ons, which is possible in certain high-mobility plasmonic media, such as graphene. Our research plan is to harness this effect and d,emonstrate an experimental proof-of-concept in the mid-infrared spectral region using nanostructured current-biased metasurfaces. If, successful, this may open an entirely new field of research, namely, nonreciprocal nonmagnetic thermal photonics, which would pro,vide a long-sought practical method to control light emission and absorption without the constraints of time-reversal symmetry and r,eciprocity. This would make a big impact since the main challenge for photonic thermal control and energy harvesting is indeed the r,eciprocal nature of wave propagation in conventional media. Breaking the symmetry between absorptivity and emissivity would allow de,signing (i) materials that absorb without emitting (in a given direction), for efficient thermal/solar radiation harvesting reaching, the ultimate Landsberg limit, as well as for thermal camouflaging and invisibility, and (ii) materials that emit without absorbing,(in a given direction), potentially very useful for enhanced radiative cooling technologies, which are becoming increasingly importa,nt for both terrestrial applications (reducing the energy consumption of active cooling) and space applications (where radiative emi,ssion is the only cooling option). Nonreciprocal thermal emitters and absorbers may find ,to the DoD and the Navy, including for enhanced capabilities in thermal management, stealth, and electricity generation. Our proof-o,f-concept demonstration of the proposed nonreciprocal nonmagnetic thermal-photonic platform will prove the feasibility of these idea,s and show a realistic path to harness these exciting opportunities.APPROVED FOR PUBLIC RELEASE
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 05, 2022
- Source ID
- N000142212486
Entities
People
- Francesco Monticone
Organizations
- Cornell University
- Office of Naval Research
- United States Navy