Second Sound in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>SrTiO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>

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

doi:10.1103/physrevlett.99.265502

Cited by 57 publications

(50 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Materials in hydrodynamic regimes can host second sound [11][12][13][14][15][16] , and is thus interesting to discuss its existence or characteristics in two dimensions. We define second sound, following ref.…”

Section: Boltzmann Transport Equationmentioning

confidence: 99%

“…Phonons in the hydrodynamic regime can, under specific conditions, form packets that alter the typical diffusive behaviour of heat and make it propagate as a damped wave, giving origin to the phenomenon of second sound, where a localized heating perturbation generates two sound wavefronts when probed at a certain distance 11,12 . This phenomenon has not been extensively studied, as to-date it was possible to observe it only in few materials at cryogenic temperatures (10 K or less): solid helium 13 , sodium fluoride 11,14 , bismuth 12 , strontium titanate 15,16 (theoretically it is also been hypothesized for diamond 17 ).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Phonon hydrodynamics in two-dimensional materials

et al. 2015

View full text Add to dashboard Cite

The conduction of heat in two dimensions displays a wealth of fascinating phenomena of key relevance to the scientific understanding and technological applications of graphene and related materials. Here, we use density-functional perturbation theory and an exact, variational solution of the Boltzmann transport equation to study fully from first-principles phonon transport and heat conductivity in graphene, boron nitride, molybdenum disulphide and the functionalized derivatives graphane and fluorographene. In all these materials, and at variance with typical three-dimensional solids, normal processes keep dominating over Umklapp scattering well-above cryogenic conditions, extending to room temperature and more. As a result, novel regimes emerge, with Poiseuille and Ziman hydrodynamics, hitherto typically confined to ultra-low temperatures, characterizing transport at ordinary conditions. Most remarkably, several of these two-dimensional materials admit wave-like heat diffusion, with second sound present at room temperature and above in graphene, boron nitride and graphane.

show abstract

Section: Boltzmann Transport Equationmentioning

confidence: 99%

mentioning

confidence: 99%

Phonon hydrodynamics in two-dimensional materials

et al. 2015

View full text Add to dashboard Cite

show abstract

“…[2]); these are now viewed as arising from more pedestrian origins and not super at all. Shortly thereafter Courtens et al [3,4], based upon a small unexplained splitting in transverse acoustic phonon energies, proposed the existence of second sound in the same temperature range [5], the present consensus is that this arises from small displacements of Sr ions along [111] directions that lower the tetragonal symmetry below $70 K and remove vibrational mode degeneracies. But the strontium titanate saga continues, exacerbated or enhanced by the ferroelectricity of O-18 SrTiO 3 and by the novel superconductivity of semiconducting strontium titanate of both oxygen isotopes [6].…”

mentioning

confidence: 99%

Domains within Domains and Walls within Walls: Evidence for Polar Domains in CryogenicSrTiO3

et al. 2013

View full text Add to dashboard Cite

Resonant piezoelectric spectroscopy shows polar resonances in paraelectric SrTiO 3 at temperatures below 80 K. These resonances become strong at T < 40 K. The resonances are induced by weak electric fields and lead to standing mechanical waves in the sample. This piezoelectric response does not exist in paraelastic SrTiO 3 nor at temperatures just below the ferroelastic phase transition. The interpretation of the resonances is related to ferroelastic twin walls which become polar at low temperatures in close analogy with the known behavior of CaTiO 3 . SrTiO 3 is different from CaTiO 3 , however, because the wall polarity is thermally induced; i.e., there exists a small temperature range well below the ferroelastic transition point at 105 K where polarity appears on cooling. As the walls are atomistically thin, this transition has the hallmarks of a two-dimensional phase transition restrained to the twin boundaries rather than a classic bulk phase transition.

show abstract

“…Later studies of the CP in SrTiO 3 were performed in a lower temperature range using a Fabry-Perot inter ferometer with good spectral resolution [17][18][19]. Therefore, it seems urgent to study the temperature dependence of the CP in the strontium titanate crystal in wide temperature and frequency ranges and to com prehensively measure CP parameters near the phase transition temperature at T c = 106 K.…”

Section: Introductionmentioning

confidence: 98%