Exclusion principle and theLandauer-Buttiker formalism The Landauer-Buttiker formalism has been very successful in describingelectronic. Landauer-Büttiker formalism. Calculation of the electronic current flowing through a system due to application of external bias voltage is one of the most difficult. Landauer-Büttiker formalism. Examples. Farkas Dániel Gergely. Msc physics student. 1. Contents. Difference of potencials; Difference of temperatures.
|Published (Last):||17 August 2010|
|PDF File Size:||9.27 Mb|
|ePub File Size:||9.73 Mb|
|Price:||Free* [*Free Regsitration Required]|
Ballistic thermal transport has been observed in multiple materials systems .
From Wikipedia, the free encyclopedia. Normally, transport of electrons or holes is dominated by scattering events, which relax the carrier momentum in an effort to bring the conducting material to equilibrium.
In terms of scattering mechanisms, optical phonon emission normally dominates, depending on the material and transport conditions.
The size and distribution of these contact spots is governed by the topological structures of the contacting surfaces forming the electrical contact. March Learn how and when to remove this template message. Articles needing cleanup from March All pages needing cleanup Cleanup tagged articles with a reason field from March Wikipedia pages needing cleanup from March All articles with unsourced statements Articles with bkttiker statements from July Articles with unsourced statements from June Articles with unsourced statements from February bittiker Without scattering, formallsm simply obey Newton’s second law of motion at non-relativistic speeds.
Ballistic conduction is not limited to electrons or holes but can also apply to phonons. The specific problem is: Ballistic conduction differs from superconductivity due to the absence of the Meissner effect in the material.
Different materials have buttuker scattering probabilities which cause different incoherence rates stochasticity. In particular, for surfaces with high fractal dimension contact spots may be very small.
Electrical contacts resulting in ballistic electron conduction are known as Sharvin Contacts.
The mean free path can be increased by reducing the number of impurities in a crystal or by lowering its temperature. Consider a coherent source of electrons connected to a conductor. A ballistic conductor would stop conducting if the driving force is turned off, whereas in a superconductor current would continue to flow after the driving supply is disconnected.
Such a transport regime has been found to depend on the nanoribbon edge structure and the electron energy. Conversely, the quantum confinement in the 1D GNR channel constricts the number of modes to carrier degeneracy and restrictions from the energy dispersion relationship and the Brillouin zone.
Ballistic transport is coherent in wave mechanics terms. Over a limited distance, the electron wave function will remain coherent. Retrieved from ” https: A comparison with fkrmalism provides an analogy between ballistic and non-ballistic conduction.
Phys. Rev. B 45, () – Exclusion principle and the Landauer-B\”uttiker formalism
There are also other scattering mechanisms which apply to different carriers that are not considered here e. From the resistance point of view, stochastic not oriented movement of electrons is useless even if they carry the same energy — they move thermally. This is because there is an energy to be paid to extract the electron from the medium work function.
Nanoelectronics Charge carriers Mesoscopic physics.
Ballistic conduction is the unimpeded flow of charge, or energy-carrying particles, over relatively long distances in a material. Thus, ballistic transport in a material is determined by how ballistically conductive that material is. In mesoscopic physicsBallistic conduction ballistic transport is labdauer transport of charge carriers in a medium usually electronshaving negligible electrical resistivity caused by scattering.
Electrons which undergo inelastic interaction are then similar to non-monochromatic light.
As mentioned, nanostructures such as carbon nanotubes or graphene nanoribbons are often considered ballistic, but these devices only very closely resemble ballistic conduction. Electronic Transport in Mesoscopic Systems. See List of thermal conductivities.
Thus the quantum conductance is approximately the same if measured at A landaue B or C and D. The widely encountered phenomenon of electrical contact resistance or ECR, arises as an electric current flowing through a rough interface is restricted to a limited number of contact spots.
For example, ballistic transport can be observed in a metal nanowire: It is theoretically possible for ballistic conduction to be extended to other quasi-particles, but this has not been experimentally verified.