The realization of ballistic graphene pn-junctions is an essential task in order to study Klein tunneling phenomena. Here we show that intercalation of Ge under the buffer layer of pre-structured SiC-samples succeeds to make truly nano-scaled pn-junctions. By means of local tunneling spectroscopy the junction width is found to be as narrow as 5 nm which is a hundred times smaller compared to el...

We present a theoretical scheme that seamlessly handles the crossover from fully ballistic to diffusive thermal transport regimes and apply it to carbon nanotubes. At room temperature, the micrometer-length nanotubes belong to the intermediate regime in which ballistic and diffusive phonons coexist, and the thermal conductance exhibits anomalous nonlinear tube-length dependence due to this coex...

We study interaction-induced quantum correction deltasigma(alphabeta) to the conductivity tensor of electrons in two dimensions for arbitrary Ttau, where T is the temperature and tau the transport mean free time. A general formula is derived, expressing deltasigma(alphabeta) in terms of classical propagators ("ballistic diffusons"). The formalism is used to calculate the interaction contributio...

We studied the phononic heat transfer through an atomic dielectric wire with both infinite and finite lengths by using a model Hamiltonian approach. At low temperature under ballistic transport, the thermal conductance contributed by each phonon branch of a uniform and harmonic chain cannot exceed the well-known value which depends linearly on temperature but is material independent. We predict...

Ballistic phonon transport was observed in Si films containing Ge nanodots. In SiGe nanodots, thermal conductivity drastically reduced close to that of amorphous materials due alloy scattering and nanodot scattering.

Abstract. We use a fully self-consistent three-dimensional quantum mechanical transport formalism to examine the performance of InAs based quantum wire transistors both in the ballistic limit and with phonon scattering included. We present a method for the inclusion of polar optical phonon scattering as a real-space self-energy term. We find that the ballistic performance of the devices can be ...

Within the last several years, a large number of experiments concerning metallic wire contacts have been carried out using a scanning tunneling microscope and a mechanically controllable break junction. Recently, the unique phenomena of ballistic electron transport through nanoscale junctions such as quantized conductance have been observed experimentally and theoretically. In this situation, f...

We describe a theoretical approach to transport and a potentially valuable scheme for screening gate dielectric materials. Realistic structural models of the Si-dielectric interface are employed for Si-SiO2-Si model metal-oxide–semiconductor ~MOS! structures. The leakage current for a 1.02-nm MOS structure is calculated from first principles using Landauer’s ballistic transport approach and ab ...

We have fabricated a sub-micron-sized structure consisting of an InAs-based 2DEG, two narrow Nb leads and a gate, where the indirect ballistic transport between the non-oppositely superconducting contacts can be controlled by the voltage applied to the gate. This new kind of tuneable junction can be used for applications and allows several fundamental questions related to the transport mechanis...

We report direct imaging of nanoscale thermal transport in single and few-layer graphene with approximately 50 nm lateral resolution using high vacuum scanning thermal microscopy. We observed increased heat transport in suspended graphene where heat is conducted by ballistic phonons, compared to adjacent areas of supported graphene, and observed decreasing thermal conductance of supported graph...