scholarly journals Characteristics of acoustic phonon transport and thermal conductance in quasi-one-dimensional quantum waveguides with semi-circular-arc cavity

2008 ◽  
Vol 57 (5) ◽  
pp. 3100
Author(s):  
Yao Ling-Jiang ◽  
Wang Ling-Ling
Keyword(s):  
Acoustic Phonon ◽  
Thermal Conductance ◽  
Phonon Transport ◽  
Circular Arc ◽  
One Dimensional ◽  
Quantum Waveguides

scholarly journals Characteristics of acoustic phonon transport and thermal conductance in multi-terminal graphene junctions

2016 ◽  
Vol 65 (8) ◽  
pp. 086301
Author(s):  
Qing Qian-Jun ◽  
Zhou Xin ◽  
Xie Fang ◽  
Chen Li-Qun ◽  
Wang Xin-Jun ◽  
...  
Keyword(s):  
Acoustic Phonon ◽  
Thermal Conductance ◽  
Phonon Transport

Acoustic phonon transport and thermal conductance in a periodically modulated quantum wire

2007 ◽  
Vol 40 (5) ◽  
pp. 1497-1500 ◽  
Author(s):  
Li-Ming Tang ◽  
Lingling Wang ◽  
Wei-Qing Huang ◽  
B S Zou ◽  
Ke-Qiu Chen
Keyword(s):  
Quantum Wire ◽  
Acoustic Phonon ◽  
Thermal Conductance ◽  
Phonon Transport

Thermal transport of small systems

2017 ◽  
Author(s):  
Takahiro Yamamoto ◽  
Kazuyuki Watanabe ◽  
Satoshi Watanabe
Keyword(s):  
Thermal Transport ◽  
Thermal Conductance ◽  
Transmission Function ◽  
Mean Free Path ◽  
Phonon Transport ◽  
Fourier Law ◽  
Small Systems ◽  
One Dimensional ◽  
Sample Dimension ◽  
The Mean

This article focuses on the phonon transport or thermal transport of small systems, including quasi-one-dimensional systems such as carbon nanotubes. The Fourier law well describes the thermal transport phenomena in normal bulk materials. However, it is no longer valid when the sample dimension reduces down to below the mean-free path of phonons. In such a small system, the phonons propagate coherently without interference with other phonons. The article first considers the Boltzmann–Peierls formula of diffusive phonon transport before discussing coherent phonon transport, with emphasis on the Landauer formulation of phonon transport, ballistic phonon transport and quantized thermal conductance, numerical calculation of the phonon-transmission function, and length dependence of the thermal conductance.

Acoustic phonon transport and ballistic thermal conductance through a three-dimensional double-bend quantum structure

2008 ◽  
Vol 104 (5) ◽  
pp. 054312 ◽  
Author(s):  
Fang Xie ◽  
Ke-Qiu Chen ◽  
Y. G. Wang ◽  
Qing Wan ◽  
B. S. Zou ◽  
...  
Keyword(s):  
Acoustic Phonon ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Phonon Transport ◽  
Quantum Structure

THE COMPARING OF ACOUSTIC PHONON TRANSPORT ABOUT MONOCHROMATIC MODE AND MIXING MODE THROUGH A DOUBLE T-SHAPED QUANTUM WAVEGUIDE

2011 ◽  
Vol 25 (30) ◽  
pp. 2313-2321 ◽  
Author(s):  
GUO-JUN YI ◽  
KE-MIN LI ◽  
LI-MING TANG ◽  
XIAO-HUA CHEN
Keyword(s):  
Thermal Conductivity ◽  
Acoustic Phonon ◽  
Mode Conversion ◽  
Coupling Effect ◽  
Thermal Conductance ◽  
Scattering Matrix ◽  
Phonon Transport ◽  
Sh Wave ◽  
Quantum Waveguide ◽  
Scattering Matrix Method

We compare the thermal conductance of SH mode and mixing mode of acoustic phonons in a double T-shaped quantum waveguide at low enough temperatures by using the scattering-matrix method, and analyze the influence from mode conversion. Our results show that the small changes of the geometric parameters can induce different variation on the thermal conductivity, where the effect of the stub height of SH wave is the strongest. Moreover, the mode conversion plays an important role on the thermal conductivity, especially at the higher temperatures, and the coupling effect between two stubs at mixing mode is larger than that at single SH mode.

ACOUSTIC PHONON TRANSPORT THROUGH A QUANTUM WAVEGUIDE WITH TWO PARTLY-OVERLAPPED STUBS

2009 ◽  
Vol 23 (19) ◽  
pp. 2353-2360
Author(s):  
HONGJIAN LI ◽  
SHUHUAN YAN ◽  
HAIYAN ZHANG ◽  
SUXIA XIE ◽  
XIN ZHOU
Keyword(s):  
Low Temperature ◽  
Acoustic Phonon ◽  
Ballistic Transport ◽  
Thermal Conductance ◽  
Scattering Matrix ◽  
Phonon Transport ◽  
Quantum Waveguide ◽  
Mode Splitting ◽  
Scattering Matrix Method ◽  
Stress Free Boundary

By using the scattering matrix method, we investigate the effect of two partly-overlapped stubs in a quantum waveguide on acoustic phonon transport and thermal conductance at low temperature. We demonstrate that the transmission coefficient is of the quantum characteristic and shows obvious discrepancies for the different discontinuity structures. The number of the stop-frequency depends on the value of the stubs' heights and ballistic transport for the mode 0 is possible when the stress-free boundary conduction is used. In addition, the thermal conductance exhibits mode-splitting behavior and sensitively depends on the heights and widths of the two partly-overlapped stubs.

Acoustic phonon transport and thermal conductance in a multiple channels nanostructure

2007 ◽  
Vol 364 (3-4) ◽  
pp. 343-347 ◽  
Author(s):  
Liu-Ying Nie ◽  
Lingling Wang ◽  
L.H. Zhao ◽  
Ke-Qiu Chen
Keyword(s):  
Acoustic Phonon ◽  
Thermal Conductance ◽  
Phonon Transport ◽  
Multiple Channels

scholarly journals Nanoscale Quantum Thermal Conductance at Water Interface: Green’s Function Approach Based on One-Dimensional Phonon Model

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1185
Author(s):  
Toshihito Umegaki ◽  
Shigenori Tanaka
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Thermal Conductance ◽  
Transmission Function ◽  
Transmission Probability ◽  
Phonon Transport ◽  
Tunnel Effect ◽  
Water Molecules ◽  
One Dimensional ◽  
Phonon Model

We have derived the fundamental formula of phonon transport in water for the evaluation of quantum thermal conductance by using a one-dimensional phonon model based on the nonequilibrium Green’s function method. In our model, phonons are excited as quantum waves from the left or right reservoir and propagate from left to right of H 2 O layer or vice versa. We have assumed these reservoirs as being of periodic structures, whereas we can also model the H 2 O sandwiched between these reservoirs as having aperiodic structures of liquid containing N water molecules. We have extracted the dispersion curves from the experimental absorption spectra of the OH stretching and intermolecular modes of water molecules, and calculated phonon transmission function and quantum thermal conductance. In addition, we have simplified the formulation of the transmission function by employing a case of one water molecule (N=1). From this calculation, we have obtained the characteristic that the transmission probability is almost unity at the frequency bands of acoustic and optical modes, and the transmission probability vanishes by the phonon attenuation reflecting the quantum tunnel effect outside the bands of these two modes. The classical limit of the thermal conductance calculated by our formula agreed with the literature value (order of 10 − 10 W/K) in high temperature regime (>300 K). The present approach is powerful enough to be applicable to molecular systems containing proteins as well, and to evaluate their thermal conductive characteristics.

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