纳米技术-自然2013-09-05 2:58 AM

Observation of room-temperature ballistic thermal conduction persisting over 8.3 [micro]m in SiGe nanowires : Nature Nanotechnology : Nature Publishing Group

n ballistic thermal conduction, the wave characteristics of phonons allow the transmission of energy without dissipation. However, the observation of ballistic heat transport at room temperature is challenging because of the short phonon mean free path. Here we show that ballistic thermal conduction persisting over 8.3 µm can be observed in SiGe nanowires with low thermal conductivity for a wide range of structural variations and alloy concentrations. We find that an unexpectedly low percentage (~0.04%) of phonons carry out the heat conduction process in SiGe nanowires, and that the ballistic phonons display properties including non-additive thermal resistances in series, unconventional contact thermal resistance, and unusual robustness against external perturbations. These results, obtained in a model semiconductor, could enable wave-engineering of phonons and help to realize heat waveguides, terahertz phononic crystals and quantum phononic/thermoelectric devices ready to be integrated into existing silicon-based electronics.

KEYWORDS

SHARE & LIKE

COMMENTS

ABOUT THE AUTHOR

纳米技术-自然

0 Following 0 Fans 0 Projects 5 Articles

SIMILAR ARTICLES

Materials with very low thermal conductivity are of great interest for both thermoelectric and optical phase-change applications. Synthetic nanostructu

Read More

Spin-polarized currents provide a powerful means of manipulating the magnetization of nanodevices, and give rise to spin transfer torques that can driv

Read More

n ballistic thermal conduction, the wave characteristics of phonons allow the transmission of energy without dissipation. However, the observation of b

Read More

The ferromagnet/oxide interface is key to developing emerging multiferroic and spintronic technologies with new functionality. Here we probe the Fe/MgO

Read More

The development of personalized medicine—in which medical treatment is customized to an individual on the basis of genetic information—requires techniq

Read More