Enhanced Photon Tunneling by Surface Plasmon–Phonon Polaritons in Graphene/hBN Heterostructures

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
B. Zhao ◽  
Z. M. Zhang
Keyword(s):  
Heat Transfer ◽  
Surface Plasmon ◽  
Chemical Potential ◽  
Near Field ◽  
Tunneling Probability ◽  
Monolayer Graphene ◽  
Field Energy ◽  
Support Surface ◽  
Photon Tunneling ◽  
Phonon Polaritons

Enhancing photon tunneling probability is the key to increasing the near-field radiative heat transfer between two objects. It has been shown that hexagonal boron nitride (hBN) and graphene heterostructures can enable plentiful phononic and plasmonic resonance modes. This work demonstrates that heterostructures consisting of a monolayer graphene on an hBN film can support surface plasmon–phonon polaritons that greatly enhance the photon tunneling and outperform individual structures made of either graphene or hBN. Both the thickness of the hBN films and the chemical potential of graphene can affect the tunneling probability, offering potential routes toward passive or active control of near-field heat transfer. The results presented here may facilitate the system design for near-field energy harvesting, thermal imaging, and radiative cooling applications based on two-dimensional materials.

Photon Tunneling via Coupling Graphene Plasmons With Phonon Polaritons of Hexagonal Boron Nitride in Reststrahlen Bands

2021 ◽  
Author(s):  
Ruiyi Liu ◽  
Xiaohu Wu ◽  
Zheng Cui
Keyword(s):  
Boron Nitride ◽  
Chemical Potential ◽  
Hexagonal Boron Nitride ◽  
Near Field ◽  
Tunneling Probability ◽  
Coupling Mechanism ◽  
Work Study ◽  
Photon Tunneling ◽  
Phonon Polaritons ◽  
Graphene Plasmons

Abstract The photon tunneling probability is the most important thing in near-field radiative heat transfer (NFRHT). This work study the photon tunneling via coupling graphene plasmons with phonon polaritons in hexagonal boron nitride (hBN). We consider two cases of the optical axis of hBN along z-axis and x-axis, respectively. We investigate the NFRHT between graphene-covered bulk hBN, and compare it with that of bare bulk hBN. Our results show that in Reststrahlen bands, the coupling of graphene plasmons and phonon polaritons in hBN can either suppress or enhance the photon tunneling probability, depending on the chemical potential of graphene and frequency. This conclusion holds when the optiacal axis of hBN is either along z-axis or x-axis. The findings in this work not only deepen our understanding of coupling mechanism between graphene plasmons with phonon polaritons, but also provide a theoretical basis for controlling photon tunneling in graphene covered hyperbolic materials.

Casimir Friction and Near-field Radiative Heat Transfer in Graphene Structures

2017 ◽  
Vol 72 (2) ◽  
pp. 171-180 ◽  
Author(s):  
A.I. Volokitin
Keyword(s):  
Heat Transfer ◽  
Energy Transfer ◽  
Transfer Coefficient ◽  
Graphene Sheet ◽  
Drift Velocity ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Near Field ◽  
Radiative Energy ◽  
Phonon Polaritons

AbstractThe dependence of the Casimir friction force between a graphene sheet and a (amorphous) SiO2 substrate on the drift velocity of the electrons in the graphene sheet is studied. It is shown that the Casimir friction is strongly enhanced for the drift velocity above the threshold velocity when the friction is determined by the resonant excitation of the surface phonon–polaritons in the SiO2 substrate and the electron–hole pairs in graphene. The theory agrees well with the experimental data for the current–voltage dependence for unsuspended graphene on the SiO2 substrate. The theories of the Casimir friction and the near-field radiative energy transfer are used to study the heat generation and dissipation in graphene due to the interaction with phonon–polaritons in the (amorphous) SiO2 substrate and acoustic phonons in graphene. For suspended graphene, the energy transfer coefficient at nanoscale gap is ~ three orders of magnitude larger than the radiative heat transfer coefficient of the blackbody radiation limit.

Near-Field Radiative Heat Transfer Between Two α-MoO3 Biaxial Crystals

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Xiaohu Wu ◽  
Ceji Fu ◽  
Zhuomin M. Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Hexagonal Boron Nitride ◽  
Near Field ◽  
Radiative Heat Flux ◽  
Relative Rotation ◽  
Maximum Heat ◽  
Phonon Polaritons

Abstract The near-field radiative heat transfer (NFRHT) between two semi-infinite α-MoO3 biaxial crystals is investigated numerically based on the fluctuation–dissipation theorem combined with the modified 4 × 4 transfer matrix method in this paper. In the calculations, the near-field radiative heat flux (NFRHF) along each of the crystalline directions of α-MoO3 is obtained by controlling the orientation of the biaxial crystals. The results show that much larger heat flux than that between two semi-infinite hexagonal boron nitride can be achieved in the near-field regime, and the maximum heat flux is along the [001] crystalline direction. The mechanisms for the large radiative heat flux are explained as due to existence of hyperbolic phonon polaritons (HPPs) inside α-MoO3 and excitation of hyperbolic surface phonon polaritons (HSPhPs) at the vacuum/α-MoO3 interfaces. The effect of relative rotation between the emitter and the receiver on the heat flux is also investigated. It is found that the heat flux varies significantly with the relative rotation angle. The modulation contrast can be as large as two when the heat flux is along the [010] direction. We attribute the large modulation contrast mainly to the misalignment of HSPhPs and HPPs between the emitter and the receiver. Hence, the results obtained in this work may provide a promising way for manipulating near-field radiative heat transfer between anisotropic materials.

Near-Field Radiative Energy Transfer Between Two Spheres

2006 ◽  
Author(s):  
Arvind Narayanaswamy ◽  
Dye-Zone Chen ◽  
Gang Chen
Keyword(s):  
Energy Transfer ◽  
Near Field ◽  
Resonance Region ◽  
Dipole Approximation ◽  
Radiative Energy ◽  
Field Energy ◽  
Support Surface ◽  
Pronounced Increase ◽  
Radiative Energy Transfer ◽  
Polar Materials

Radiative energy transfer between closely spaced bodies is known to be significantly larger than that predicted by classical radiative transfer because of tunneling due to evanescent waves. Polar materials like silicon carbide and silica can support surface phonon polaritons due to resonances in the dielectric function of such materials. This leads to an enhanced density of states of electromagnetic surface modes near the surface compared to vacuum and leads to a pronounced increase in energy transfer near the resonance region. Experimental measurements between half-planes of polar materials can be very challenging because of the difficulty in measuring the gap as well as the parallelism between the surfaces. Theoretical investigation of near-field energy transfer on the other hand, is generally restricted to that between two parallel half-planes because of the complications involved in analyzing other configurations such as sphere-sphere or sphere-plane. Sphere-sphere or sphere-plane configurations beyond the dipole approximation have not been attempted. In this work, we analyze numerically the radiative energy transfer between two adjacent non-overlapping spheres.

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