Active control of near-field radiative heat transfer through nonreciprocal graphene surface plasmons

Abstract

In this Rapid Communication, we theoretically demonstrate that near-field radiative heat transfer (NFRHT) can be modulated and enhanced by a new energy transmission mode of evanescent wave, i.e. the nonreciprocal surface plasmons polaritons (NSPPs). In addition to the well-known coupled surface plasmon polaritons (SPPs), applying a drift current on a graphene sheet leads to an extremely asymmetric photonic transmission model, which has never been noted in the noncontact heat exchanges at nanoscale before. The coupling of plasmons in the infrared bands dominates the NFRHT, associated with low loss (high loss and ultrahigh confinement) traveling along (against) the current. The dependence of NSPPs on the drift-current velocity as well as the vacuum gap is analyzed. It is found that the coupling of NSPPs at smaller and larger gap sizes exhibits different nonreciprocities. Finally, we also demonstrate that the prominent influence of the drift current on the radiative heat flux is found at a low chemical potential. These findings will open a new way to spectrally control NFRHT, which holds great potential for improving the performance of energy systems like near-field thermophotovoltaics and thermal modulator.

Polariton topological transition effects on radiative heat transfer

“…Moreover, as the two bodies are brought into proximity, the evanescent field of HSPPs associated with two graphene gratings can interact with each other, leading to the two dispersion curves at the higher wave-vector region and the smaller wave-vector region. However, due to the existence of the attenuation length [δ z = 1/Im(k z )] [18], the surface state dominated by dispersion at the higher wave-vector region is easily filtered by the vacuum gap, and cannot make a corresponding contribution to the NFRHT. Therefore, in the subsequent analysis, we only show the dispersion relationship at the smaller wave-vector region, unless otherwise stated.…”

“…In particular, the nearfield radiative heat transfer (NFRHT) can be far ahead of the blackbody limit, either theoretically or experimentally, via the resonant coupling of surface phonon polaritons (SPhPs) [13] or surface plasmon polaritons (SPPs) [14]. Moreover, the development in fabrication of metamaterials results in extensive studies of the coupling of surface polaritons for NFRHT between metamaterials in theory, such as hyperbolic polaritons [15], magnetoplasmon polaritons [16], ellipse polaritons [17], nonreciprocal polaritons [18], and nonreciprocal hyperbolic polaritons [19]. Various types of surface polaritons have been extensively studied for their ability to dominate the photon tunneling and greatly modulate the near-field heat transfer.…”

Thermal switch with multiple discrete levels

“…[39]). The optical conductivity for the array of graphene nanoribbons has been derived using a well-known effective medium theory (EMT) [10][11][12] that holds true when the unit-cell period P=W+G is much smaller than the operating wavelength, i.e., P ≪ λ0. Meanwhile, in references, [40][41][42] EMT is valid only when the vacuum gap is larger than the period of the ribbons.…”

“…Meanwhile, researches on nanoscale thermal radiation have shown that the radiant energy exchanges in near field can exceed that predicted by Planck's law by a few orders of magnitude. [9][10][11][12][13][14][15] The surface plasmon or phonon polaritons (SPhPs) effect can significantly enhance the near-field thermal radiation. These facts make it possible to improve significantly the discrete degree of the thermal signal of radiative thermal switch.…”

Twist-induced control of near-field heat radiation between magnetic Weyl semimetals

“…For novel applications, it is of importance to actively control NFRHT. Several strategies have been proposed, such as applying an electric field to phase-change materials [24] or ferroelectric materials [25], applying an external magnetic field to magnetooptical materials [26][27][28][29][30][31], using drift currents [32,33], and regulating the chemical potential of photons [34]. Another active control strategy is to utilize the rotational degree of freedom [35][36][37][38][39][40][41].…”