THERMAL TRANSPORT BY BALLISTIC PHONON IN A SEMICONDUCTOR RECTANGULAR QUANTUM WIRE MODULATED WITH QUANTUM DOT

2009 ◽  
Vol 23 (30) ◽  
pp. 3597-3607 ◽  
Author(s):  
XIAO-YAN YU ◽  
XIAO-FANG PENG ◽  
KE-QIU CHEN
Keyword(s):  
Quantum Dot ◽  
Thermal Transport ◽  
Low Temperatures ◽  
Quantum Wire ◽  
Thermal Conductance ◽  
Phonon Transport ◽  
Total Transmission ◽  
Coefficient Versus ◽  
Increasing Temperature ◽  
Scattering Matrix Method

Thermal transport by ballistic phonon in a semiconductor rectangular quantum wire modulated with quantum dot at low temperatures is investigated with the use of the scattering matrix method. The calculated results show that the total transmission coefficient versus the reduced phonon frequency exhibits interesting characteristics such as inhomogeneous quantum transport steps. Quantized thermal conductance plateau can be observed at low temperatures, and the thermal conductance is not increased monotonically with increasing temperature. The results also show that the phonon transport probability and thermal conductance can be controlled to a certain degree by adjusting the parameters of the proposed quantum structure.

scholarly journals Temperature and interlayer coupling induced thermal transport across graphene/2D-SiC van der Waals heterostructure

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Md. Sherajul Islam ◽  
Imon Mia ◽  
A. S. M. Jannatul Islam ◽  
Catherine Stampfl ◽  
Jeongwon Park
Keyword(s):  
High Temperatures ◽  
Thermal Transport ◽  
Van Der Waals ◽  
Thermal Conductance ◽  
Interlayer Coupling ◽  
Phonon Modes ◽  
Out Of Plane ◽  
System Temperature ◽  
Non Equilibrium Molecular Dynamics ◽  
Increasing Temperature

AbstractGraphene based two-dimensional (2D) van der Waals (vdW) materials have attracted enormous attention because of their extraordinary physical properties. In this study, we explore the temperature and interlayer coupling induced thermal transport across the graphene/2D-SiC vdW interface using non-equilibrium molecular dynamics and transient pump probe methods. We find that the in-plane thermal conductivity κ deviates slightly from the 1/T law at high temperatures. A tunable κ is found with the variation of the interlayer coupling strength χ. The interlayer thermal resistance R across graphene/2D-SiC interface reaches 2.71 $$\times$$ × 10–7$${\text{Km}}^{2} /{\text{W}}$$ Km 2 / W at room temperature and χ = 1, and it reduces steadily with the elevation of system temperature and χ, demonstrating around 41% and 56% reduction with increasing temperature to 700 K and a χ of 25, respectively. We also elucidate the heat transport mechanism by estimating the in-plane and out-of-plane phonon modes. Higher phonon propagation possibility and Umklapp scattering across the interface at high temperatures and increased χ lead to the significant reduction of R. This work unveils the mechanism of heat transfer and interface thermal conductance engineering across the graphene/2D-SiC vdW heterostructure.

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

Quantized thermal conductance at low temperatures in quantum wire with catenoidal contacts

2010 ◽  
Vol 81 (19) ◽  
Author(s):  
Xiao-Fang Peng ◽  
Ke-Qiu Chen ◽  
Qing Wan ◽  
B. S. Zou ◽  
Wenhui Duan
Keyword(s):  
Low Temperatures ◽  
Quantum Wire ◽  
Thermal Conductance

Thermal conductance associated with six types of vibration modes in quantum wire modulated with quantum dot

2014 ◽  
Vol 378 (30-31) ◽  
pp. 2195-2200 ◽  
Author(s):  
Xiao-Fang Peng ◽  
Xin-Jun Wang ◽  
Li-Qun Chen ◽  
Jian-Bo Li ◽  
Wu-Xing Zhou ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Wire ◽  
Thermal Conductance ◽  
Vibration Modes

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.

BALLISTIC PHONON TRANSPORT THROUGH GAUSSIAN ACOUSTIC NANOCAVITIES

2011 ◽  
Vol 25 (19) ◽  
pp. 1631-1642 ◽  
Author(s):  
SHU-JUAN LI ◽  
GUI-FANG HUANG ◽  
YUAN CHEN ◽  
WEI-QING HUANG ◽  
WANGYU HU ◽  
...  
Keyword(s):  
Band Gap ◽  
Low Temperatures ◽  
Gaussian Function ◽  
Thermal Conductance ◽  
Wide Band ◽  
Phonon Transport ◽  
Transmission Spectra ◽  
Wide Band Gap ◽  
Semiconductor Nanowire ◽  
Ballistic Phonons

We investigate ballistic phonon transport through Gaussian acoustic nanocavities in a semiconductor nanowire at low temperatures. When the transverse widths of acoustic nanocavities takes a Gaussian function, it is found that wide band gap and resonant peaks appear in transmission spectra. The phonon-cavity confined modes exist as the number of the nanocavities is large. The phonon transmission and thermal conductance strongly depend on the number and length of nanocavities. The results suggest that the Gaussian acoustic nanocavities may be useful for controlling thermal conductance artificially and the design of phonon devices to manipulate ballistic phonons in nanophononics.

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.

Ballistic thermal transport properties at low temperatures in semiconductor nanowires-based heterojunctions

2016 ◽  
Vol 30 (10) ◽  
pp. 1650134 ◽  
Author(s):  
Xia Yu ◽  
Zhong-Xiang Xie ◽  
Jun-Hun Liu ◽  
Qiao Chen ◽  
Ke-Min Li ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Transport Properties ◽  
Transmission Coefficient ◽  
Thermal Transport ◽  
Low Temperatures ◽  
Thermal Conductance ◽  
Semiconductor Nanowires ◽  
Width Ratio ◽  
Slant Angle ◽  
Thermal Transport Properties

In this paper, we study ballistic thermal transport properties at low temperatures in semiconductor nanowires-based heterojunctions under hard-wall boundary conditions (HWBCs) and stress-free boundary conditions (SFBCs). Here, the numerical calculations for the asymmetric heterojunction (ASHJ) and symmetric heterojunction (SHJ) are done. When SFBCs are employed, the transmission coefficient exhibits different behaviors between ASHJ and SHJ especially at low frequency, but when HWBCs are employed, the transmission coefficient displays similar smooth platforms in both heterojunctions. In low temperature limit, the quantized thermal conductance can be observed in SHJ under SFBCs regardless of the structural details. However, this quantization cannot be observed in ASHJ under SFBCs, and the thermal conductance is strongly sensitive to the transverse width ratio rather than the slant angle. With increasing the transverse width ratio, the thermal conductance in both heterojunctions gradually increases especially, and such the increasing degree is more evident at higher temperatures. A brief analysis of these results is given.

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