Mesoscopic phonon transmission through a nanowire-bulk contact
نویسندگان
چکیده
We calculate the frequency-dependent mesoscopic acoustic phonon transmission probability through the abrupt junction between a semi-infinite, one-dimensional cylindrical quantum wire and a three-dimensional bulk insulator, using a perturbative technique that is valid at low frequency. The system is described using elasticity theory, and traction-free boundary conditions are applied to all free surfaces. In the low-frequency limit the transmission probability vanishes as v2, the transport being dominated by the longitudinal channel, which produces a monopole source of elastic radiation at the surface of the bulk solid. The thermal conductance between an equilibrated wire nonadiabatically coupled to a bulk insulator should therefore vanish with temperature as T3.
منابع مشابه
Phonon Transport Across Mesoscopic Constrictions
Phonon transport across constrictions formed by a nanowire or a nanoparticle on a substrate is studied by a numerical solution of the gray Boltzmann transport equation (BTE) resolving the effects of two length scales that govern problems of practical importance. Predictions of total thermal resistance for wire/substrate and particle/substrate combinations are made for the entire range of Knudse...
متن کاملMesoscopic thermal transport through a weak link
We consider mesoscopic thermal transport between two bulk dielectrics joined by a narrow wire or weak mechanical link. In the ‘‘tunneling’’ regime where the phonon transmission probability through the link is small and the thermal conductance is much less than pk BT=6_; the thermal current is determined by a product of the local vibrational spectral densities of the two bodies. We derive an exp...
متن کاملThermal conductivity suppression in bismuth nanowires
The thermal conductivity of individual bismuth nanowires was characterized using a suspended microdevice and correlated with the crystal structure and growth direction obtained by transmission electron microscopy on the same nanowires. Compared to bulk bismuth in the same crystal direction perpendicular to the trigonal axis, the thermal conductivity of a single-crystal bismuth nanowire of 232 n...
متن کاملTemperature Dependence of Electrical and Thermal Conduction in Single Silver Nanowire
In this work, the thermal and electrical transport in an individual silver nanowire is characterized down to 35 K for in-depth understanding of the strong structural defect induced electron scattering. The results indicate that, at room temperature, the electrical resistivity increases by around 4 folds from that of bulk silver. The Debye temperature (151 K) of the silver nanowire is found 36% ...
متن کاملPhonon thermal conductivity suppression of bulk silicon nanowire composites for efficient thermoelectric conversion.
Vertically-aligned silicon nanowires (SiNWs) that demonstrate reductions of phonon thermal conductivities are ideal components for thermoelectric devices. In this paper, we present large-area silicon nanowire arrays in various lengths using a silver-induced, electroless-etching method that is applicable to both n- and p-type substrates. The measured thermal conductivities of nanowire composites...
متن کامل