scispace - formally typeset
Journal ArticleDOI

Conductance viewed as transmission

Yoseph Imry, +1 more
- 01 Mar 1999 - 
- Vol. 71, Iss: 2, pp 515-525
TLDR
In this article, Anderson et al. proposed a totally quantum-mechanical approach to calculate conductance in cases where the carriers have a quantum mechanically coherent history within the sample, making it essential to take the interfaces into account.
Abstract
Early quantum theories of electrical conduction were semiclassical. Electrons were accelerated according to Bloch’s theorem; this was balanced by back scattering due to phonons and lattice defects. Cross sections for scattering, and band structures, were calculated quantum-mechanically, but the balancing process allowed only for occupation probabilities, not permitting a totally coherent process. Also, in most instances, scatterers at separate locations were presumed to act incoherently. Totally quantum-mechanical theories stem from the 1950s, and have diverse sources. Particularly intense concern with the need for more quantum mechanical approaches was manifested in Japan, and Kubo’s formulation became the most widely accepted version. Quantum theory, as described by the Schrodinger equation, is a theory of conservative systems, and does not allow for dissipation. The Schrodinger equation readily allows us to calculate polarizability for atoms, molecules, or other isolated systems that do not permit electrons to enter or leave. Kubo’s linear-response theory is essentially an extended theory of polarizability. Some supplementary handwaving is needed to calculate a dissipative effect such as conductance, for a sample with boundaries where electrons enter and leave (Anderson, 1997). After all, no theory that ignores the interfaces of a sample to the rest of its circuit can possibly calculate the resistance of such a sample of limited extent. Modern microelectronics has provided the techniques for fabricating very small samples. These permit us to study conductance in cases where the carriers have a totally quantum mechanically coherent history within the sample, making it essential to take the interfaces into account. Mesoscopic physics, concerned with samples that are intermediate in size between the atomic scale and the macroscopic one, can now demonstrate in manufactured structures much of the quantum mechanics we associate with atoms and molecules.

read more

Citations
More filters
Journal ArticleDOI

Advances in molecular quantum chemistry contained in the Q-Chem 4 program package

Yihan Shao, +156 more
- 17 Jan 2015 - 
TL;DR: A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided in this paper, covering approximately the last seven years, including developments in density functional theory and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces.
Journal ArticleDOI

Physical one-way functions

TL;DR: The concept of fabrication complexity is introduced as a way of quantifying the difficulty of materially cloning physical systems with arbitrary internal states as primitives for physical analogs of cryptosystems.
Journal ArticleDOI

Molecular Electronics with Carbon Nanotubes

TL;DR: In this article, the authors review the electrical properties of carbon nanotubes, and then focus on carbon Nanotube field effect transistors (CNTFETs) and compare their electrical properties with those of Si MOSFETs.
Journal ArticleDOI

Carbon nanotube electronics

TL;DR: In this paper, the potential of carbon nanotubes (CNTs) as the basis for a new nanoelectronic technology was evaluated and compared to those of corresponding silicon devices.
Journal ArticleDOI

Driven quantum transport on the nanoscale

TL;DR: In this paper, the authors explore the prospects to control by use of time-dependent fields quantum transport phenomena in nanoscale systems and study for driven conductors the electron current and its noise properties.
References
More filters
Book

An introduction to the bootstrap

TL;DR: This article presents bootstrap methods for estimation, using simple arguments, with Minitab macros for implementing these methods, as well as some examples of how these methods could be used for estimation purposes.
Book

Electronic transport in mesoscopic systems

TL;DR: In this article, preliminary concepts of conductance from transmission, S-matrix and Green's function formalism are discussed. And double-barrier tunnelling is considered.
Journal ArticleDOI

Scaling Theory of Localization: Absence of Quantum Diffusion in Two Dimensions

TL;DR: In this paper, it was shown that the conductance of disordered electronic systems depends on their length scale in a universal manner, and asymptotic forms for the scaling function were obtained for both two-dimensional and three-dimensional systems.

Electronic Transport in Mesoscopic Systems

TL;DR: In this article, preliminary concepts of conductance from transmission, S-matrix and Green's function formalism are discussed. And double-barrier tunnelling is considered.