The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Sergei A Tretyakov - One of the best experts on this subject based on the ideXlab platform.

  • Overcoming Black Body Radiation limit in free space: Metamaterial superemitter
    New Journal of Physics, 2016
    Co-Authors: Stanislav I. Maslovski, Constantin R. Simovski, Sergei A Tretyakov
    Abstract:

    Here, we demonstrate that the power spectral density of thermal Radiation at a specific wavelength produced by a Body of finite dimensions set up in free space under a fixed temperature could be made theoretically arbitrary high, if one could realize double negative metamaterials with arbitrary small loss and arbitrary high absolute values of permittivity and permeability (at a given frequency). This result refutes the widespread belief that Planck's law itself sets a hard upper limit on the spectral density of power emitted by a finite macroscopic Body whose size is much greater that the wavelength. Here we propose a physical realization of a metamaterial emitter whose spectral emissivity can be greater than that of the ideal Black Body under the same conditions. Due to the reciprocity between the heat emission and absorption processes such cooled down superemitter also acts as an optimal sink for the thermal Radiation --- the "thermal Black hole" --- which outperforms Kirchhoff-Planck's Black Body which can absorb only the rays directly incident on its surface. The results may open a possibility to realize narrowband super-Planckian thermal radiators and absorbers for future thermo-photovoltaic systems and other devices.

  • overcoming Black Body Radiation limit in free space metamaterial thermal Black hole
    arXiv: Optics, 2014
    Co-Authors: Stanislav I. Maslovski, Constantin R. Simovski, Sergei A Tretyakov
    Abstract:

    Here, we theoretically demonstrate that the power spectral density of thermal Radiation at a specific wavelength produced by a Body of finite dimensions set up in free space under a fixed temperature can be made arbitrary high. Essentially, we refute the widespread belief that Planck's law sets a hard upper limit on the spectral density of power emitted by a hot macroscopic Body. We prove that Radiation above this "limit" is possible even for optically large (but finite) isotropic emitters, by a process of resonant tunneling of photons associated with emitter's dark modes, which are irradiated to far zone under certain conditions that we identify. We designate the emitter satisfying these conditions as "thermal Black hole", in contrast to the usual term "Black Body" which is commonly attributed to an object which absorbs all rays incident on its surface. We show that although the effective spectral emissivity of a thermal Black hole can be much greater than unity, it contradicts neither the second law of thermodynamics, nor properly amended Kirchhoff's law of thermal Radiation. We propose a physical realization of such a truly super-Planckian emitter.

V Badescu - One of the best experts on this subject based on the ideXlab platform.

Austin J Minnich - One of the best experts on this subject based on the ideXlab platform.

  • phonon Black Body Radiation limit for heat dissipation in electronics
    Nature Materials, 2015
    Co-Authors: Joel Schleeh, J Mateos, I Iniguezdelatorre, Niklas Wadefalk, Perake Nilsson, Jan Grahn, Austin J Minnich
    Abstract:

    Thermal dissipation at the active region of electronic devices is a fundamental process of considerable importance. Inadequate heat dissipation can lead to prohibitively large temperature rises that degrade performance, and intensive efforts are under way to mitigate this self-heating. At room temperature, thermal resistance is due to scattering, often by defects and interfaces in the active region, that impedes the transport of phonons. Here, we demonstrate that heat dissipation in widely used cryogenic electronic devices instead occurs by phonon Black-Body Radiation with the complete absence of scattering, leading to large self-heating at cryogenic temperatures and setting a key limiton the noise floor. Our result has important implications for the many fields that require ultralow-noise electronic devices.

Stanislav I. Maslovski - One of the best experts on this subject based on the ideXlab platform.

  • Overcoming Black Body Radiation limit in free space: Metamaterial superemitter
    New Journal of Physics, 2016
    Co-Authors: Stanislav I. Maslovski, Constantin R. Simovski, Sergei A Tretyakov
    Abstract:

    Here, we demonstrate that the power spectral density of thermal Radiation at a specific wavelength produced by a Body of finite dimensions set up in free space under a fixed temperature could be made theoretically arbitrary high, if one could realize double negative metamaterials with arbitrary small loss and arbitrary high absolute values of permittivity and permeability (at a given frequency). This result refutes the widespread belief that Planck's law itself sets a hard upper limit on the spectral density of power emitted by a finite macroscopic Body whose size is much greater that the wavelength. Here we propose a physical realization of a metamaterial emitter whose spectral emissivity can be greater than that of the ideal Black Body under the same conditions. Due to the reciprocity between the heat emission and absorption processes such cooled down superemitter also acts as an optimal sink for the thermal Radiation --- the "thermal Black hole" --- which outperforms Kirchhoff-Planck's Black Body which can absorb only the rays directly incident on its surface. The results may open a possibility to realize narrowband super-Planckian thermal radiators and absorbers for future thermo-photovoltaic systems and other devices.

  • overcoming Black Body Radiation limit in free space metamaterial thermal Black hole
    arXiv: Optics, 2014
    Co-Authors: Stanislav I. Maslovski, Constantin R. Simovski, Sergei A Tretyakov
    Abstract:

    Here, we theoretically demonstrate that the power spectral density of thermal Radiation at a specific wavelength produced by a Body of finite dimensions set up in free space under a fixed temperature can be made arbitrary high. Essentially, we refute the widespread belief that Planck's law sets a hard upper limit on the spectral density of power emitted by a hot macroscopic Body. We prove that Radiation above this "limit" is possible even for optically large (but finite) isotropic emitters, by a process of resonant tunneling of photons associated with emitter's dark modes, which are irradiated to far zone under certain conditions that we identify. We designate the emitter satisfying these conditions as "thermal Black hole", in contrast to the usual term "Black Body" which is commonly attributed to an object which absorbs all rays incident on its surface. We show that although the effective spectral emissivity of a thermal Black hole can be much greater than unity, it contradicts neither the second law of thermodynamics, nor properly amended Kirchhoff's law of thermal Radiation. We propose a physical realization of such a truly super-Planckian emitter.

Sándor Varró - One of the best experts on this subject based on the ideXlab platform.

  • The digital randomness of Black-Body Radiation
    Journal of Physics: Conference Series, 2013
    Co-Authors: Sándor Varró
    Abstract:

    The statistical properties of the fractional part of the random energy of a spectral component of Black-Body Radiation have been analysed in the frame of classical Kolmogorovian probability theory. Besides the integer part of the energy (which satisfies the well-known Planck- Bose distribution) the realizations of its fractional part (related to 'round-off errors') has been represented by binary sequences, like z = 0.001011000010.... It has been shown that the binary variables realized by the 0-s and 1-s at different positions are independent. From the condition of independence the original distribution of the fractional part z can be recovered. If these binary variables have the same distribution, they describe a temperature-independent (random) energy, whose expectation value is the well-known zero-point energy. Thus, the zero-point fluctuations can be considered as a physical representative of an ideal random number generator.

  • irreducible decomposition of gaussian distributions and the spectrum of Black Body Radiation
    Physica Scripta, 2007
    Co-Authors: Sándor Varró
    Abstract:

    It is shown that the energy of a mode of a classical chaotic field, following the continuous exponential distribution as a classical random variable, can be uniquely decomposed into a sum of its fractional part and of its integer part. The integer part is a discrete random variable (we call it the Planck variable) whose distribution is just the Bose distribution yielding Planck's law of Black-Body Radiation. The fractional part is the 'dark part' represented by the 'dark variable' with a continuous distribution, which is, of course, not observed in the experiments. It is proved that the Bose distribution is infinitely divisible, and the irreducible decomposition of it is given. This means that the Planck variable can be decomposed into an infinite sum of independent binary random variables representing the 'binary photons' (more accurately photo-molecules or photo-multiplets) of energies 2sh? with s=0, 1, 2,?.... These binary photons follow Fermi statistics. According to our present analysis, the Black-Body Radiation can be viewed as a mixture of statistically and thermodynamically independent fermion gases consisting of 'binary photons'. The binary photons give a natural tool for the dyadic expansion of arbitrary (but not coherent) ordinary photon excitations. It is shown that the binary photons have wave?particle fluctuations of fermions. These fluctuations combine to give the wave?particle fluctuations of the original bosonic photons, expressed by Einstein's fluctuation formula.

  • a study on Black Body Radiation classical and binary photons
    arXiv: Quantum Physics, 2006
    Co-Authors: Sándor Varró
    Abstract:

    The present study gives a detailed analysis of the Black-Body Radiation based on classical random variables. It is shown that the energy of a mode of a chaotic Radiation field (Gauss variable) can be uniquely decomposed into a sum of a discrete variable (Planck variable having the Planck-Bose distribution) and a continuous dark variable (with a truncated exponential distribution of finite support). The Planck variable is decomposed, on one hand, into a sum of binary variables representing the binary photons of energies 2^s*h*nu with s=0,1,2,etc. In this way the Black-Body Radiation can be viewed as a mixture of thermodinamically independent fermion gases. The Planck variable can also be decomposed into a sum of independent Poisson components representing the classical photo-molecules of energies m*h*nu with m=1,2,3,etc. These classical photons have only particle-like fluctuations, on the other hand, the binary photons have wave-particle fluctuations of fermionic character.

  • a study on Black Body Radiation classical and binary photons
    Acta Physica Hungarica A) Heavy Ion Physics, 2006
    Co-Authors: Sándor Varró
    Abstract:

    The present study gives a detailed analysis of the thermal Radiation based completely on classical random variables. It is shown that the energy of a mode of a classical chaotic Radiation field, following the continuous exponential distribution as a classical random variable (Gauss variable), can be uniquely decomposed into a sum of its fractional part and of its integer part. The integer part is a discrete random variable (Planck variable) whose distribution is just the Planck-Bose distribution, yielding Planck’s law of Black-Body Radiation. The fractional part is the dark part (dark variable) with a continuous distribution, which is not observed in the experiments, since Planck’s law describes the observations with an unprecedented accuracy. It is proved that the Planck-Bose distribution is infinitely divisible, and can be decomposed in two ways. On one hand, the Planck variable can be decomposed into an infinite sum of independent binary random variables representing the binary photons (more accurately binary photo-molecules or photo-multiplets) of energy 2 s hv with s=0, 1, 2, .... These binary photons follow the Fermi statistics, and they serve as a unique irreducible decomposition of the Planck variable. In this way, the Black-Body Radiation can be viewed as a mixture of thermodynamically independent fermion gases consisting of binary photons. On the other hand, the Planck variable is decomposed into a series of Poisson random variables which describe classical photons (more accurately Poissonian photomolecules, or photo-multiplets) of energy mhv, where m=1, 2, .... This way the Black-Body Radiation is decomposed into a mixture of thermodynamically independent gases consisting of the photo-molecules satisfying the Boltzmann statistics. From the contribution of the first-order photo-molecules we obtain the Wien formula, from the whole series we recover the Planck formula. It is shown that the classical photons have only particle-like fluctuations, on the other hand, the binary photons have wave-particle fluctuations of fermions. Both of these fluctuations combine to give the wave-particle fluctuations of the original bosonic photons, yielding Einstein’s fluctuation formula.

  • irreducible decomposition of gaussian distributions and the spectrum of Black Body Radiation
    arXiv: Quantum Physics, 2006
    Co-Authors: Sándor Varró
    Abstract:

    It is shown that the energy of a mode of a classical chaotic field, following the continuous exponential distribution as a classical random variable, can be uniquely decomposed into a sum of its fractional part and of its integer part. The integer part is a discrete random variable (we call it Planck variable) whose distribution is just the Bose distribution yielding the Planck law of Black-Body Radiation. The fractional part is the dark part (we call is dark variable) with a continuous distribution, which is, of course, not observed in the experiments. It is proved that the Bose distribution is infinitely divisible, and the irreducible decomposition of it is given. The Planck variable can be decomposed into an infinite sum of independent binary random variables representing the binary photons (more accurately photo-molecules or photo-multiplets) of energies 2^s*h*nu with s=0,1,2... . These binary photons follow the Fermi statistics. Consequently, the Black-Body Radiation can be viewed as a mixture of statistically and thermodynamically independent fermion gases consisting of binary photons. The binary photons give a natural tool for the dyadic expansion of arbitrary (but not coherent) ordinary photon excitations. It is shown that the binary photons have wave-particle fluctuations of fermions. These fluctuations combine to give the wave-particle fluctuations of the original bosonic photons expressed by the Einstein fluctuation formula.