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We present a phenomenological force-constant model developed for the description of lattice dynamics of sp2 hybridized carbon networks. Within this model approach, we introduce a new set of parameters to calculate the phonon dispersion of…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 J. Zimmermann , P. Pavone , G. Cuniberti

Mode space approach has been used so far in NEGF to treat phonon scattering for computational efficiency. Here we perform a more rigorous quantum transport simulation in real space to consider interband scatterings as well. We show a…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Youngki Yoon , Dmitri E. Nikonov , Sayeef Salahuddin

Interfaces impede heat flow in micro/nanostructured systems. Conventional theories for interfacial thermal transport were derived based on bulk phonon properties of the materials making up the interface without explicitly considering the…

Phonon transmission across an interface between dissimilar crystalline solids is calculated using molecular dynamics simulations with interatomic force constants obtained from first principles. The results reveal that although inelastic…

Computational Physics · Physics 2015-06-09 Takuru Murakami , Takuma Hori , Takuma Shiga , Junichiro Shiomi

The thermal properties of graphitic ribbon are investigated based on Brenner's empirical potential. The reliability and usefulness of the empirical potential to address the thermal properties of covalent-bonded carbon nanostructures are…

Materials Science · Physics 2009-11-10 Takahiro Yamamoto , Kazuaki Mii , Kazuyuki Watanabe

A complex approach phonon quantum discrete model (PQDM) was developed to describe dynamics, kinetics and statistics of phonons in carbon nanostructures with zero-chirality of both zig-zag and armchair geometry. The model allows include into…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 E. Ya. Glushko , V. N. Evteev , M. V. Moiseenko , N. A. Slusarenko , A. A. Zakhidov

Interfaces play an essential role in phonon-mediated heat conduction in solids, impacting applications ranging from thermoelectric waste heat recovery to heat dissipation in electronics. From the microscopic perspective, interfacial phonon…

Mesoscale and Nanoscale Physics · Physics 2017-05-24 Chengyun Hua , Xiangwen Chen , Navaneetha K. Ravichandran , Austin J. Minnich

Recently, an anisotropic Debye model [Dames et al., Physical Review B 87, 12 (2013)] was proposed for calculations of the interfacial thermal conductance and the minimum thermal conductivity of graphite-like layered materials. Despite…

Applied Physics · Physics 2018-12-13 Hongkun Li , Weidong Zheng , Yee Kan Koh

Acoustic phonon transport is revealed as a potential radiation-to-conduction transition mechanism for single-digit nanometer vacuum gaps. To show this, we measure heat transfer from a feedback-controlled platinum nanoheater to a laterally…

Traditional theories of interfacial heat transfer by atomic vibrations, also known as phonons, do not explain how vibrational mode interactions contribute to interface conductance. Traditional methods also use the concept of phonons as…

Materials Science · Physics 2021-01-26 Andrew Rohskopf

We present experimental measurements of the thermal boundary conductance (TBC) from $77 - 500$ K across isolated heteroepitaxially grown ZnO films on GaN substrates. These data provide an assessment of the assumptions that drive the phonon…

We numerically investigate thermal transport at solid-solid interfaces with graded intermediate layers whose masses vary exponentially from one side to the other. Using Non-Equilibrium Green's Function and Non-Equilibrium Molecular Dynamics…

A semi-analytical model for studying thermal transport at the nanoscale, able to accurately describe both the effect of out of equilibrium transport and the thermal transfer at interfaces, is presented. Our approach is based on the…

Mesoscale and Nanoscale Physics · Physics 2020-06-26 B. Davier , P. Dollfus , S. Volz , J. Shiomi , J. Saint-Martin

We propose systems that allow a tuning of the phonon transmission function T($\omega$) in graphene nanoribbons by using C$^{13}$ isotope barriers, antidot structures, and distinct boundary conditions. Phonon modes are obtained by an…

Mesoscale and Nanoscale Physics · Physics 2015-07-15 P. Scuracchio , A. Dobry , F. Peeters , S. Costamagna

Despite the ubiquity of applications of heat transport across nanoscale interfaces, including integrated circuits, thermoelectrics, and nanotheranostics, an accurate description of phonon transport in these systems remains elusive. Here we…

Mesoscale and Nanoscale Physics · Physics 2019-09-11 Georgios Varnavides , Adam S. Jermyn , Polina Anikeeva , Prineha Narang

Recent experimental advances probing coherent phonon and electron transport in nanoscale devices at contact have motivated theoretical channel-based analyses of conduction based on the nonequilibrium Green's function formalism. The…

Mesoscale and Nanoscale Physics · Physics 2020-08-12 Prashanth S. Venkataram , Sean Molesky , Juan Carlos Cuevas , Alejandro W. Rodriguez

We study ballistic interfacial thermal transport across atomic junctions. Exact expressions for phonon transmission coefficients are derived for thermal transport in one-junction and two-junction chains, and verified by numerical…

Materials Science · Physics 2011-03-02 Lifa Zhang , Pawel Keblinski , Jian-Sheng Wang , Baowen Li

We present a study of the phononic thermal conductivity of isotopically disordered carbon nanotubes. In particular, the behavior of the thermal conductivity as a function of the system length is investigated, using Green's function…

Materials Science · Physics 2008-11-03 Gabriel Stoltz , Michele Lazzeri , Francesco Mauri

The transmission of acoustic phonons is an important element in the design and performance of nano-mechanical devices operating in the mesoscopic limit. Analytic expressions for the power transmission coefficient, T, exist only in the…

Applied Physics · Physics 2019-03-27 John Bartlett , Karwan Rostem , Edward Wollack

We theoretically elucidate the transfer of phonon angular momentum by acoustic modes across a smooth interface between crystals. We analyze this process, which is difficult to describe with the conventional acoustic mismatch model, using a…

Mesoscale and Nanoscale Physics · Physics 2026-01-28 Yuta Suzuki , Shuntaro Sumita , Yusuke Kato