scholarly journals Near-complete violation of Kirchhoff’s law in thermal radiation in ultrathin magnetic Weyl semimetal films

2021 ◽  
Author(s):  
Jun Wu ◽  
Zhong Wang ◽  
Han Zhai ◽  
Zhangxing Shi ◽  
Xiaohu Wu ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Weyl Semimetal ◽  
Kirchhoff's Law

Experimental Verification of Kirchhoff’s Law on Thermal Radiation at an Electromagnetic Wave Level

2007 ◽  
Author(s):  
Hidenobu Wakabayashi ◽  
Toshiro Makino
Keyword(s):  
Electromagnetic Wave ◽  
Thermal Radiation ◽  
Experimental Verification ◽  
Phase Matching ◽  
Emission Sources ◽  
Spherical Waves ◽  
Energy Equilibrium ◽  
Kirchhoff's Law

The Kirchhoff’s law on emission and absorption of thermal radiation is a law driven deductively for the energy equilibrium of thermal radiation. First, we consider on the basis of spectroscopic experiments and an electromagnetism whether the Kirchhoff’s law is valid for the spectra of emission and absorption of an electromagnetic wave which are characterized by the phase as well as the amplitude of the wave. The interference of radiation caused by the phase matching is a key for this problem. Second, we consider the possibility of systematic coherency of spherical waves emitted by a number of dipoles which are the sources of thermal radiation. This consideration is related to the validity of the assumption that emission sources of thermal radiation move randomly.

scholarly journals Near-complete violation of Kirchhoff’s law of thermal radiation with a 03  T magnetic field

2019 ◽  
Vol 44 (17) ◽  
pp. 4203 ◽  
Author(s):  
Bo Zhao ◽  
Yu Shi ◽  
Jiahui Wang ◽  
Zhexin Zhao ◽  
Nathan Zhao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Radiation ◽  
Kirchhoff's Law

Experimental Verification of Kirchhoff’s Thermal Radiation Law on Surfaces With Emittance Spectra Characterized by Optical Interference Phenomena

2010 ◽  
Author(s):  
Toshiro Makino ◽  
Hidenobu Wakabayashi
Keyword(s):  
Thermal Radiation ◽  
Plane Waves ◽  
Experimental System ◽  
Normal Incidence ◽  
Complementary Relation ◽  
Spherical Waves ◽  
Hemispherical Reflectance ◽  
Electric Dipoles ◽  
Narrow Spectral Region ◽  
Kirchhoff's Law

This paper discusses Kirchhoff’s law on thermal radiation. The logic of derivation of the law is reconsidered, first. Then, spectra of normal emittance εN and normal incidence hemispherical reflectance RNH are measured on surfaces whose microstructure changes in a non-equilibrium experimental system to examine the validity of the complementary relation between εN and RNH, which is the suggestion of Kirchhoff’s law. As the results of the examination, it is illustrated experimentally on a variety of surfaces that the complementary relation is valid within an experimental uncertainty. Provided this conclusion is admitted, the followings are suggested. If a surface is designed so that it does not reflect a narrow spectral region of radiation to any direction and reflects the other spectral regions of radiation much over the hemisphere, then the surface can be a new spectrally-functional emitter of radiation. It is also suggested that thermal radiation emitted at a surface is considered as the emission of plane waves at the surface rather than as the emission of spherical waves by electric dipoles.

scholarly journals Combined modelling of shortwave and thermal radiation for one-imensional SVATs

1999 ◽  
Vol 3 (1) ◽  
pp. 15-30 ◽  
Author(s):  
D. Pearson ◽  
C. C. Daamen ◽  
R. J. Gurney ◽  
L. P. Simmonds
Keyword(s):  
Thermal Radiation ◽  
Computational Cost ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Geometric Effect ◽  
Optical Part ◽  
Kirchhoff's Law ◽  
Upwelling And Downwelling

Abstract. Expressions for the upwelling and downwelling fluxes of optical and thermal radiation between soil, vegetation and the sky are derived, under certain simple assumptions. These are that interception of radiation by the vegetation is a purely geometric effect, while scattering is isotropic, with a strength given by a single-scattering albedo in the optical part of the spectrum, and by Kirchhoff's Law in the thermal. The soil is assumed to be a lambertian reflector, also scattering according to an albedo and Kirchhoff's Law. The model, called RM, conserves energy exactly. As part of a SVAT, it is driven by measured insolation instead of radiation, with little increase in computational cost and number of parameters.

scholarly journals Generalization of Kirchhoff’s Law: The inherent relations between quantum efficiency and emissivity

2022 ◽  
Author(s):  
Matej Kurtulik ◽  
Michal Shimanovich ◽  
Rafi Weill ◽  
Assaf Manor ◽  
Michael Shustov ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Quantum Efficiency ◽  
Chemical Potential ◽  
Thermal Emission ◽  
Photon Emission ◽  
The Body ◽  
Energy Devices ◽  
Planck’S Law ◽  
Electron Photon ◽  
Kirchhoff's Law

Abstract Planck’s law of thermal radiation depends on the temperature, \(T\), and the emissivity, \(\epsilon\), which is the coupling of heat to radiation depending on both phonon-electron nonradiative-interactions and electron-photon radiative-interactions. In contrast, absorptivity, \(\alpha\), only depends on the electron-photon radiative-interactions. At thermodynamic equilibrium, nonradiative-interactions are balanced, resulting in Kirchhoff’s law of thermal radiation, \(\epsilon =\alpha\). For non-equilibrium, Quantum efficiency (QE) describes the statistics of photon emission, which like emissivity depends on both radiative and nonradiative interactions. Past generalized Planck’s equation extends Kirchhoff’s law out of equilibrium by scaling the emissivity with the pump-dependent chemical-potential \(\mu\), obscuring the relations between the body properties. Here we theoretically and experimentally demonstrate a prime equation relating these properties in the form of \(\epsilon =\alpha \left(1-QE\right)\). At equilibrium, these relations are reduced to Kirchhoff’s law. Our work lays out the evolution of non-thermal emission with temperature, which is critical for the development of lighting and energy devices.

scholarly journals Thermal radiation of Er doped dielectric crystals: Probing the range of applicability of the Kirchhoff’s law

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Ekembu K. Tanyi ◽  
Brandi T. Burton ◽  
Evgenii E. Narimanov ◽  
M. A. Noginov
Keyword(s):  
Thermal Radiation ◽  
Er Doped ◽  
Kirchhoff's Law
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