The near-field scanning thermal microscope

Wischnath, Uli F.; Welker, Joachim; Munzel, M.; Kittel, A.

doi:10.1063/1.2955764

Cited by 64 publications

(53 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In terms of the energy transmission between two bodies the black body case corresponds to maximum transmission for all allowed frequencies ω and all wave vectors smaller than ω/c, where c is the vacuum light velocity. This means that all the propagating modes are perfectly transmitted across the separation gap.In the near-field regime, i.e., for distances smaller than the thermal wavelength λ th = c/k B T (2π is Planck's constant, k B is Boltzmann's constant, and T is the temperature) the radiative heat flux is not due to the propagating modes, but it is dominated by evanescent waves [2-4] and especially surface polaritons as confirmed by recent experiments [5][6][7][8][9][10][11]. The common paradigm is that the largest heat flux can be achieved when the materials support surface polaritons which will give a resonant energy transfer restricted to a small frequency band around the surface mode resonance frequency [3,4,12,13].…”

mentioning

confidence: 88%

Hyperbolic Metamaterials as an Analog of a Blackbody in the Near Field

2012

View full text Add to dashboard Cite

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.PACS numbers: 44.40.+a;81.05.Xj A black body is usually defined by its property of having a maximum absorptivity and therefore also a maximum emissivity by virtue of Kirchhoff's law [1]. The energy transmission between two black bodies having different temperatures obey the well-known Stefan-Boltzmann law. This law sets an upper limit for the power which can be transmitted by real materials, but it is itself a limit for the far-field only, since it takes only propagating modes into account. In terms of the energy transmission between two bodies the black body case corresponds to maximum transmission for all allowed frequencies ω and all wave vectors smaller than ω/c, where c is the vacuum light velocity. This means that all the propagating modes are perfectly transmitted across the separation gap.In the near-field regime, i.e., for distances smaller than the thermal wavelength λ th = c/k B T (2π is Planck's constant, k B is Boltzmann's constant, and T is the temperature) the radiative heat flux is not due to the propagating modes, but it is dominated by evanescent waves [2-4] and especially surface polaritons as confirmed by recent experiments [5][6][7][8][9][10][11]. The common paradigm is that the largest heat flux can be achieved when the materials support surface polaritons which will give a resonant energy transfer restricted to a small frequency band around the surface mode resonance frequency [3,4,12,13]. Many researchers have tried to find materials enhancing the nanoscale heat flux due to the contribution of the coupled surface modes by using layered materials [14,15] In the present work the aim is twofold: (i) We show, that materials supporting a broad band of evanescent frustrated modes can outperform the heat flux due to surface modes. This provides new possibilies for designing materials giving large nanoscale heat fluxes which could be used for thermal management at the nanoscale for instance. (ii) We derive a general limit for the heat flux carried by the frustrated modes and show that it is, in fact, the near-field analog of the usual black body limit. For the evanescent modes a near field analog of a black body can be defined in the sense that the energy transmission coefficient must be equal to one for all frequencies and all wave vectors larger than ω/c. With today's nanofabrication techniques it is possible to manufacture artificial materials such as photonic band gap materials and metamaterials which exhibit very unusual material properties like negative refraction [23]. Due to such properties they are considered as good candidates for perfect lensing [24,25], for repulsive Casimir forces [26][27][28][...

show abstract

mentioning

confidence: 88%

Hyperbolic Metamaterials as an Analog of a Blackbody in the Near Field

2012

View full text Add to dashboard Cite

show abstract

“…Experiments in the nanometric regime have clearly demonstrated the transfer enhancement [21,22]. Yet the lack of good control of the tip geometry did not allow quantitative comparison with theory.…”

mentioning

confidence: 99%

Mesoscopic Description of Radiative Heat Transfer at the Nanoscale

2010

View full text Add to dashboard Cite

We present a formulation of the nanoscale radiative heat transfer (RHT) using concepts of mesoscopic physics. We introduce the analog of the Sharvin conductance using the quantum of thermal conductance. The formalism provides a convenient framework to analyse the physics of RHT at the nanoscale. Finally, we propose a RHT experiment in the regime of quantized conductance.PACS numbers: 44.40.+a;73.23.-b It has been discovered in the late sixties that the RHT between two metallic parallel plates can be larger than predicted using the blackbody radiation form [1][2][3]. It is now known that this anomalous RHT is due to the contribution of evanescent waves and becomes significant when the distance separating the interfaces becomes smaller than the thermal wavelength λ th = c kBT where is Planck's constant, k B is Boltzmann's constant, c is the light velocity and T is the temperature. Using the framework of fluctuational electrodynamics [4], Polder and van Hove (PvH) were able to derive a general form of the RHT accounting for the optical properties of the media [5]. Since this seminal contribution, several reports have been published in the literature [6][7][8][9][10][11]. A quantum-mechanical derivation [12] has confirmed these results obtained within the framework of fluctuational electrodynamics. While the first papers considered metals, it has been realized that the RHT at the nanoscale can be further enhanced for dielectrics due to the contribution of surface phonon polaritons [13,14]. Recent reviews can be found in Refs. [15][16][17][18].The first attempts to measure a heat flux between metallic surfaces at room temperature and micrometric distances have proved to be inconclusive [19,20]. Experiments in the nanometric regime have clearly demonstrated the transfer enhancement [21,22]. Yet the lack of good control of the tip geometry did not allow quantitative comparison with theory. More recent experiments [23,24] are performed using silica taking advantage of the flux enhancement due to the resonant contribution of surface phonon polaritons. A good agreement between PvH theory and experiments has been reported [24].The purpose of this paper is to establish a link between the PvH form of the radiative heat flux and the formalism of transport in mesoscopic physics. It will help to develop a more physical understanding of the RHT at the nanoscale, which also clarifies how losses and non-local effects determine the maximal achievable heat flux [10]. Finally, we will show that this reformulation raises the prospect of observing quantized conductance for systems with sizes on the order of the thermal wavelength λ th .We start our discussion with the PvH form of the RHT. We consider a vacuum gap with width d separating two homogeneous half spaces labeled medium 1 and 2 [see Fig. 1 a)]. Then, the heat flux is [5,16] ( 1) where κ = (k x , k y ) and γ = k 2 0 − κ 2 are the parallel and normal wave vector, Θ(ω,is the mean energy of a harmonic oscillator, k 0 = ω/c, r 1,2 j are the usual Fresnel factors for s-or p-polar...

show abstract

“…Current approaches include scanning thermal microscopies and time-resolved pump-probe spectroscopy. 4 The former methods use temperature-sensing tips to probe the spatial distribution of temperature, [5][6][7] while the latter approach is based on following the heat transfer kinetics after excitation of a material formed by a large ensemble of nanoobjects in a solid or liquid matrix. Its principle consists in selectively heating the nanoobjects by a "pump" pulse, and following the dynamics of their subsequent cooling by energy transfer to their environment (Fig.…”

Section: Introductionmentioning

confidence: 99%

Cooling dynamics and thermal interface resistance of glass-embedded metal nanoparticles

Juvé

Scardamaglia²,

Maioli³

et al. 2009

Phys. Rev. B

100

133

View full text Add to dashboard Cite

The cooling dynamics of glass-embedded noble metal nanoparticles with diameters ranging from 4 to 26 nm were studied using ultrafast pump-probe spectroscopy. Measurements were performed probing away from the surface plasmon resonance of the nanoparticles to avoid spurious effects due to glass heating around the particle. In these conditions, the time-domain data reflect the cooling kinetics of the nanoparticle. Cooling dynamics are shown to be controlled by both thermal resistance at the nanoparticule-glass interface, and heat diffusion in the glass matrix. Moreover, the interface conductances are deduced from the experiments and found to be correlated to the acoustic impedance mismatch at the metal/glass interface.2

show abstract

The near-field scanning thermal microscope

Cited by 64 publications

References 20 publications

Hyperbolic Metamaterials as an Analog of a Blackbody in the Near Field

Hyperbolic Metamaterials as an Analog of a Blackbody in the Near Field

Mesoscopic Description of Radiative Heat Transfer at the Nanoscale

Cooling dynamics and thermal interface resistance of glass-embedded metal nanoparticles

Contact Info

Product

Resources

About