arXiv subjects

S. -A. Biehs

Publications and source records attributed to S. -A. Biehs.

15 recordsLinked to original sources

arXiv2026

Surface-modes mediated long-range radiative heat transfer through a plasmonic Su-Schrieffer-Heeger chain

We study the radiative heat transfer through a Su-Schrieffer-Heeger chain of plasmonic InSb nanoparticles in close vicinity of an InSb substrate. We show how the frequency bands of the in-plane and out-of-plane modes in the chain are deformed by the coupling to the surface waves in the InSb substrate by considering different carrier concentrations. By calculating the Zak phase we show that also in the presence of the substrate there is a topological phase transition and that topologically protected edge modes emerge for finite chains. Finally, we demonstrate the long-range heat transport along the chain due to the coupling to the surface waves of the sample {accompanied by a non-monotonic distance dependence of this effect and we show imprints of the trivial and non-trivial phase in the photonic local density of states.} We find an enhanced heat transfer in the topological non-trivial phase compared to the trivial phase due to the contribution of the edge modes.

cond-mat.mes-hall↗

arXiv2025

Dynamical thermal near-field routing with the non-reciprocal Weyl semi-metal Co$_3$Sn$_2$S$_2$

We demonstrate theoretically the non-reciprocal heating dynamics of two nanoparticles in the vicinity of a substrate all made of the ferromagnetic Weyl semi-metal Co$_3$Sn$_2$S$_2$. We show that the thermal routing effect is due to a spin-spin coupling mechanism between the nanoparticle resonances and the non-reciprocal surface modes of the substrate. Our numerical results indicate that the non-reciprocal heating effect is on the order of 22.5% of the applied temperature differences. This strong rounting effect paves the way for first experimental realizations employing Weyl semi-metals and applications in nanoscale thermal management.

cond-mat.mes-hall↗

arXiv2025

Efficiency and Mechanism of Heat Flux Rectification with Non-Reciprocal Surface Waves in Weyl-Semi-Metals

We reinvestigate the mechanism of near-field heat transfer rectification between two Weyl semimetal nanoparticles and a planar Weyl semimetal substrate via the coupling to non-reciprocal surface modes. We first show that the previously predicted rectification ratio of 2673 is incorrect and should rather be 1502. Furthermore we show that depending on the distance between the nanoparticles there can be a much more efficient heat flux rectification with ratios of about 6000. Furthermore, we identify a previously overlooked range of forward rectification and a range of strong backward rectification with rectification ratios larger than 8000 for relatively small Weyl node separations. We investigate the mechanism behind this large heat flux rectification and study its sensitivity with respect to certain material parameters and temperature showing that even larger rectification ratios up to 15000 are possible highlighting that certain Weyl semimetals are strong candidates for highly efficient heat flux rectification.

cond-mat.mes-hall↗

arXiv2024

Residual surface charge mediated near-field radiative energy transfer: A topological insulator analog

We study the modifications of near-field radiative energy transfer (NFRET) caused by residual surface charges, which are common in micro- and nano-systems like NEMS/MEMS. The host object with the residual surface charges and the inherent bulk state can be treated as an analog of the real three-dimensional topological insulator, which is inherent of also both surface states and bulk states and is promising to modulate NFRET. Through constructing such a topological insulator analog, we aim to modulate NFRET concerning only common trivial materials. Besides the well-known resonant modes (surface polariton and localized surface polariton) supported by the bulk state, the residual surface charges give rise to an additional temperature-dependent mode providing a new heat flux channel. For low temperatures we find a giant surface-charge-induced enhancement of the NFRET due to a good match between the surface-charge-induced resonance and the Planck window. However, for relative high temperatures where the Fröhlich resonance dominates the heat transfer rather the surface-charge-induced resonance, the residual charges result in a weakening of the NFRET. This work paves way for understanding and modulating the near-field radiative energy transfer for micro- and nano-systems.

physics.app-ph↗

arXiv2023

Nonreciprocal heat flux via synthetic fields in linear quantum systems

We study the heat transfer between N coupled quantum resonators with applied synthetic electric and magnetic fields realized by changing the resonators parameters by external drivings. To this end we develop two general methods, based on the quantum optical master equation and on the Langevin equation for $N$ coupled oscillators where all quantum oscillators can have their own heat baths. The synthetic electric and magnetic fields are generated by a dynamical modulation of the oscillator resonance with a given phase. Using Floquet theory we solve the dynamical equations with both methods which allow us to determine the heat flux spectra and the transferred power. With apply these methods to study the specific case of a linear tight-binding chain of four quantum coupled resonators. We find that in that case, in addition to a non-reciprocal heat flux spectrum already predicted in previous investigations, the synthetic fields induce here non-reciprocity in the total heat flux hence realizing a net heat flux rectification.

quant-ph↗

arXiv2023

Enhancement of synthetic magnetic field induced nonreciprocity via bound states in continuum in dissipatively coupled systems

The nonreciprocal propagation of light typically requires use of materials like ferrites or magneto-optical media with a strong magnetic bias or methods based on material nonlinearities which require use of strong electromagnetic fields. A simpler possibility to produce nonreciprocity is to use spatio-temporal modulations to produce magnetic fields in synthetic dimensions. In this paper we show that dissipatively coupled systems can lead to considerable enhancement of nonreciprocity in synthetic fields. The enhancement comes about from the existence of nearly nondecaying mode -bound state in continuum (BIC) in dissipatively coupled systems. The dissipative coupling occurs in a wide class of systems coupled via transmission lines, waveguides, or nano fibers. The systems could be optical resonators or microscopic qubits. Remarkably we find that for specific choice of the modulation amplitudes, the transmission say in forward direction is completely extinguished whereas in the backward direction it becomes maximum. The synthetic fields produce transmission resonances which show significant line narrowing which owe their origin to existence of BIC's in dissipative systems.

cond-mat.mes-hall↗

arXiv2022

Breakdown of detailed balance for thermal radiation by synthetic fields

In recent times the possibility of non-reciprocity in heat transfer between two bodies has been extensively studied. In particular the role of strong magnetic fields has been investigated. A much simpler approach with considerable flexibility would be to consider heat transfer in synthetic electric and magnetic fields which are easily applied. We demonstrate the breakdown of detailed balance for the heat transfer function $\mathcal{T} (ω)$, i.e. the spectrum of heat transfer between two objects due to the presence of synthetic electric and magnetic fields. The spectral measurements carry lot more physical information and were the reason for the quantum theory of radiation. We demonstrate explicitly the synthetic field induced non-reciprocity in the heat transfer transmission function between two graphene flakes and for the Casimir coupling between two objects. Unlike many other cases of heat transfer, the latter case has interesting features of the strong coupling. Further the presence of synthetic fields affects the mean occupation numbers of two membranes and propose this system for the experimental verification of the breakdown of detailed balance.

cond-mat.mes-hall↗

arXiv2020

General trace formula for heat flux fluctuations

Within the framework of macroscopic quantum electrodynamics and scattering theory, we derive the general expressions for the variance of radiative heat transfer between two arbitrarily shaped objects placed in an arbitrary environment in terms of their T-operators. The such derived expression is valid in the far- and near-field regime of thermal radiation as well as for reciprocal and non-reciprocal objects of any size within a reciprocal or non-reciprocal environment as long as the distances between the objects and their sizes are covered by the macroscopic approach. As special cases we discuss the variance of the radiative heat flux between two nanoparticles and between a nanoparticle and a substrate in near- and far-field regime.

cond-mat.mes-hall↗

arXiv2020

Anomalous photon thermal Hall effect

We predict an anomalous thermal Hall effect (ATHE) mediated by photons in networks of Weyl semi-metals. Contrary to the photon thermal Hall effect in magneto-optical systems which requires the application of an external magnetic field the ATHE in a Weyl semi-metals network is an intrinsic property of these systems. Since the Weyl semi-metals can exhibit a strong nonreciprocal response in the infrared over a broad spectral range the magnitude of thermal Hall flux in these systems can be relatively large compared to the primary flux. This ATHE paves the way for a directional control of heat flux by localy tuning the magnitude of temperature field without changing the direction of temperature gradient.

cond-mat.mes-hall↗

arXiv2019

Green-Kubo relation for thermal radiation in non-reciprocal systems

We rederive the Green-Kubo relation establishing a connection between the near- and far-field heat transfer between two objects out of equilibrium to the equilibrium fluctuations of these objects in an arbitrary environment. Employing the scattering approach in combination with the fluctuation-dissipation theorem, we generalize the previously derived Green-Kubo expression to the case of non-reciprocal objects and non-reciprocal environments.

cond-mat.mes-hall↗

arXiv2017

Qubit entanglement across Epsilon near Zero Media

Currently epsilon near zero materials (ENZ) have become important for controlling the propagation of light and enhancing by several orders of magnitude the Kerr and other nonlinearities. Given this advance it is important to examine the quantum electrodynamic processes and information tasks near ENZ materials. We study the entanglement between two two-level systems near ENZ materials and compare our results with the case where the ENZ material is replaced by a metal. It is shown that with ENZ materials substantial entanglement can be achieved over larger distances than for metal films. We show that this entanglement over large distances is due to the fact that one can not only have large emission rates but also large energy transmission rates at the epsilon-nearzero wavelength. This establishes superiority of ENZ materials for studying processes specifically important for quantum information tasks.

quant-ph↗

arXiv2016

Long-Range Dipole-Dipole Interaction and Anomalous Förster Energy Transfer across Hyperbolic Meta Material

We study radiative energy transfer between a donor-acceptor pair across a hyperbolic metamaterial slab. We show that similar to a perfect lens a hyperbolic lens allows for giant energy transfer rates. For a realistic realization of a hyperbolic multilayer metamaterial we find an enhancement of up to three orders of magnitude with respect to the transfer rates across a plasmonic silver film of the same size especially for frequencies which coincide with the epsilon-near zero and the epsilonnear pole frequencies. Furthermore, we compare exact results based on the S-matrix method with results obtained from effective medium theory. Our finding of very large dipole-dipole interaction at distances of the order of a wavelength has important consequences for producing radiative heat transfer, quantum entanglement etc.

cond-mat.mes-hall↗

arXiv2012

Giant Spin Hall Effect in Single Photon Plasmonics

We show the existence of a very large spin Hall effect of light (SHEL) in single photon plasmonics based on spontaneous emission and the dipole-dipole interaction initiated energy transfer (FRET) on plasmonic platforms. The spin orbit coupling inherent in Maxwell equations is seen in the conversion of sigma + photon to sigma - photon. The FRET is mediated by the resonant surface plasmons and hence we find very large SHEL. We present explicit results for SHEL on both graphene and metal films. We also study how the splitting of the surface plasmon on a metal film affects the SHEL. In contrast to most other works which deal with SHEL as correction to the paraxial results, we consider SHEL in the near field of dipoles which are far from paraxial.

cond-mat.mes-hall↗

arXiv2012

Radiative cooling of nanoparticles close to a surface

We study the radiative cooling of polar and metallic nanoparticles immersed in a thermal bath close to a partially reflecting surface. The dynamics of relaxation is investigated at different distances from the surface, i.e., in the near-field and far-field zones. We demonstrate the existence of an oscillating behavior for the thermal relaxation time with respect to the separation distance from the surface, an analog of Friedel oscillations in Fermi liquids.

cond-mat.mes-hall↗

arXiv2012

Towards a black body for near-field thermal radiation

We study the near-field heat exchange between hyperbolic materials and demonstrate that these media are able to support broadband frustrated modes which transport heat by photon tunnelling with a high efficiency close to the theoretical limit. We predict that hyperbolic materials can be designed to be perfect thermal emitters at nanoscale and derive the near-field analog of the blackbody limit.

cond-mat.mes-hall↗