Light scattering in a phonon gas

Koreeda, Akitoshi; Takano, R.; Saikan, S.

doi:10.1103/physrevb.80.165104

Cited by 17 publications

(16 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is hence likely that it originates from a Raman scattering process occurring in the SiN core. Such broadband Raman scattering has been ascribed to breaking of momentum selection rules due to disorder in the amorphous material, and photon-phonon coupling due to thermal fluctuations [ 20 , 21 , 22 ]. A detailed study of the behavior of such a Raman scattering process in a guiding structure is outside the scope of this paper.…”

Section: Resultsmentioning

confidence: 99%

Silicon Nitride Background in Nanophotonic Waveguide Enhanced Raman Spectroscopy

et al. 2017

View full text Add to dashboard Cite

Abstract:Recent studies have shown that evanescent Raman spectroscopy using a silicon nitride (SiN) nanophotonic waveguide platform has higher signal enhancement when compared to free-space systems. However, signal-to-noise ratio from the waveguide at a low analyte concentration is constrained by the shot-noise from the background light originating from the waveguide itself. Hence, understanding the origin and properties of this waveguide background luminescence (WGBL) is essential to developing mitigation strategies. Here, we identify the dominating component of the WGBL spectrum composed of a broad Raman scattering due to momentum selection-rule breaking in amorphous materials, and several peaks specific to molecules embedded in the core. We determine the maximum of the Raman scattering efficiency of the WGBL at room temperature for 785 nm excitation to be 4.5 ± 1 × 10 −9 cm −1 ·sr −1 , at a Stokes shift of 200 cm −1 . This efficiency decreases monotonically for higher Stokes shifts. Additionally, we also demonstrate the use of slotted waveguides and quasi-transverse magnetic polarization as some mitigation strategies.

show abstract

Section: Resultsmentioning

confidence: 99%

Silicon Nitride Background in Nanophotonic Waveguide Enhanced Raman Spectroscopy

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Observations of second sound were made with heat pulse experiments in 3 He (between 0.42 and 0.58 K) (11), in Bi (between 1.2 and 4 K) (12), and in NaF (between 11 and 14.5 K) (13,14). The reported occurrence of second sound in SrTiO 3 at 30 to 40 K (15,16) is in dispute, as others argued that the attribution of the low-frequency doublet in the Brillouin spectra to second sound was not supported by the observations (17,18). Computational work indicated that the temperature window for the phonon hydrodynamics regime is much wider in graphene ( 9) and other twodimensional (2D) materials (19) because of strong normal scattering involving the flexural mode.…”

mentioning

confidence: 99%

Observation of second sound in graphite at temperatures above 100 K

Huberman

Duncan

Chen

et al. 2019

Science

217

193

View full text Add to dashboard Cite

Wavelike thermal transport in solids, referred to as second sound, has until now been an exotic phenomenon limited to a handful of materials at low temperatures. This has restricted interest in its occurrence and in its potential applications. Through time-resolved optical measurements of thermal transport on 5-20 μm length scales in graphite, we have made direct observations of second sound at temperatures above 100 K. The results are in qualitative agreement with ab initio calculations that predict wavelike phonon hydrodynamics on ~ 1-μm length scale up to almost room temperature. The results suggest an important role of second sound in microscale transient heat transport in two-dimensional and layered materials in a wide temperature range. One Sentence Summary:Wavelike thermal transport is observed at above 100 K and predicted at even higher temperatures, suggesting prospects for unique microscale cooling kinetics in two-dimensional and layered materials.

show abstract

“…As mentioned by Lee et al [18], these experiments can be broadly distinguished as two different methods: (a) Heat-pulse experiments and (b) Light scattering experiments. In literature, both the heat-pulse experiments [16,94,[96][97][98][99][100][101][102] and the light scattering methods [26,95,[103][104][105][106][107][108][109] have been proved to be effective to detect second sound in solids. In a standard heat pulse experiment [16,18,99], a heat pulse is generated at the one end of the sample and the temporal response of temperature is monitored at the opposite end whereas light scattering techniques measure the local change of dielectric constants due to the propagation of second sound.…”

Section: Experimental Methods and Observationsmentioning

confidence: 99%

“…However, it was found that SrTiO 3 possesses strong Normal scattering due to strongly anharmonic soft transverse optical phonons [113]. Motivated by this idea, Koreeda et al [26,108] explored low-frequency light scattering experiments without employing a thermal fluctuation field to investigate the propagation of second sound in SrTiO 3 . They observed an underdamped second sound for SrTiO 3 below 40 K [26].…”

Section: Experimental Methods and Observationsmentioning

confidence: 99%

“…Bi with sufficient isotopic purity was experimentally observed [100,153,154] to feature phonon hydrodynamics at low temperature regime (3 K < T < 3.5 K) which had been verified only few years back by Markov et al [48] via the first-principles calculations coupled with variational solution of the LBTE. Both doped and undoped SrTiO 3 had been experimentally investigated [25,108] in the context of phonon hydrodynamics and Poiseuille regime with faster than T 3 scaling was observed for thermal conductivity in the temperature range 6 K < T < 13 K for undoped SrTiO 3 . Second-principles density functional theory with full LBTE solutions by Torres et al [167] confirmed the hydrodynamic phonon transport in SrTiO 3 with smaller characteristic size of the sample (4 µm).…”

Section: D Materialsmentioning

confidence: 99%

See 1 more Smart Citation

Phonon hydrodynamics in crystalline materials

Ghosh¹,

Kusiak²,

Battaglia³

2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Phonon hydrodynamics is an exotic phonon transport phenomenon that challenges the conventional understanding of diﬀusive phonon scattering in crystalline solids. It features a peculiar collective motion of phonons with various unconventional properties resembling ﬂuid hydrodynamics, facilitating non Fourier heat transport. Hence, it opens up several new avenues to enrich the knowledge and implementations on phonon physics, phonon engineering, and micro and nanoelectronic device technologies. This review aims at covering a comprehensive development as well as the recent advancements in this ﬁeld via experiments, analytical methods, and state-of-the-art numerical techniques. The evolution of the topic has been realized using both phenomenological and material science perspectives. Further, the discussions related to the factors that inﬂuence such peculiar motion, illustrate the capability of phonon hydrodynamics to be implemented in various applications. A plethora of new ideas can emerge from the topic considering both the physics and the material science axes, navigating towards a promising outlook in the research areas around phonon transport in non-metallic solids.

show abstract

Light scattering in a phonon gas

Cited by 17 publications

References 48 publications

Silicon Nitride Background in Nanophotonic Waveguide Enhanced Raman Spectroscopy

Silicon Nitride Background in Nanophotonic Waveguide Enhanced Raman Spectroscopy

Observation of second sound in graphite at temperatures above 100 K

Phonon hydrodynamics in crystalline materials

Contact Info

Product

Resources

About