Online proceedings - EDA Publishing Association

24-26 September 2008, Rome, Italystudies show that, in contrast to the destructive interference in metals that results in thePippard ineffectiveness condition, the interference in semiconductor structuressubstantially enhances the effective electron-phonon coupling [1]. This important resultreflects the different nature of the deformation potential in metals and semiconductors. Inmetals, the deformation potential is associated with electron-gas compressibility, while insemiconductors this contribution is negligible due to the typically-small carrierconcentration. The deformation potential in semiconductors originates from a shift of theconduction band edge under the deformation, while in metals this contribution is smallbecause of strong screening. The theory developed provides an explanation for energyexchange in silicon structures and is fully supported by very recent experiments on InSi[9].Role of low-dimensionality. According to basic principles of quantum mechanics, the interactionlength l int is of the order of 1/q, where q is the momentum transferred in scattering process. Thus,for e-ph scattering in bulk conductors, l int is of the order of λ T . In low-dimensional conductors, qis the projection of q T on the conducting plane or channel. Therefore, in nanostructures, q isdetermined by intrinsic peculiarities of momentum transfer (i.e. by diffusion, plasmon, and othersingularities related to collective excitations). Therefore, the momentum transferred in lowdimensions can be significantly smaller then q T , so the corresponding interaction region will besubstantially larger than λ T [1,2]. Another reason why the energy exchange in nanoconductors isvery interesting is that nanotechnology offers many possibilities to change the screening of theinteraction between electrons and ions, i.e. the electron-phonon interaction. For example, bychanging the carrier concentration in carbon nanotubes, it is possible to change the character ofthe deformation potential (metal/semiconductor) and related effects.1. A. Sergeev, M.Yu. Reizer, and V. Mitin, Deformation electron-phonon coupling indisordered semiconductors and nanostructures. – Phys. Rev. Lett., 94, 136602 (2005).2. A. Sergeev and V. Mitin, Electron-phonon interaction in disordered conductors: Staticand vibrating scattering potentials. - Phys. Rev. B. 61, 6041-6047 (2000); Breakdown ofPippard ineffectiveness condition for phonon-electron scattering in micro andnanostructures. - Europhys. Lett. 51, 641-647 (2000).3. A. Sergeev, M. Reizer, and V. Mitin, Effects of electron-electron and electron-phononinteractions in weakly disordered conductors and heterostructures. – Phys. Rev. B. 69,075310 (2004).4. A.V. Sergeev, Electronic Kapitza resistance due to inelastic electron-boundary scattering,- Phys. Rev. B 58, R10199 (1998); Inelastic electron-boundary scattering in thin films,Physica B 263-264, 217 (1999).5. N. Vagidov, A. Sergeev, and V. Mitin, Infrared quantum-dot detectors with diffusionlimited capture, Int. J. High Speed Electronics and Systems 17, 585 (2007).6. Sergeev, M.Yu. Reizer, and V. Mitin, Heat current in the magnetic field: Nernst-Ettingshausen effect above the superconducting transition, Phys. Rev. B 77, 064501(2008).7. B. Pippard, Ultrasonic attenuation in metals, Philos. Mag. 46, 1104 (1955).8. J. J. Lin and J. P. Bird, Recent experimental studies of electron dephasing in metal andsemiconductor mesoscopic structures, J. Phys. Condens. Matter 14, R501 (2002).9. X. Z. Yu, Y. Yang, W. Pan, and W. Z. Shen, Electron-phonon interaction in disorderedsemiconductors, Appl. Phys. Lett. 92, 092106 (2008).©EDA Publishing/THERMINIC 2008 171ISBN: 978-2-35500-008-9