Generalized many-channel conductance formula with application to small rings

Abstract

The conductance of a sample scattering elastically and coupled to leads with many channels is derived. We assume that all the incident channels on one side of the sample are fed from the same chemical potential. The transmitted and reflected streams are determined by the incident streams through the multichannel scattering properties of the sample. We do not assume that the channels equilibrate with each other. Our result differs from those given earlier by other authors, except for that of Azbel [J. Phys. C 14, L225 (1981)],which is confirmed. We point out that a similar result is obtained for the conductance in a single channel at a temperature above zero. As an application, we obtain the dependence on channel number N of the contributions to the conductance of a small ring, periodic in the Aharonov-Bohm flux through it. Terms whose period is h/e as well as those with period h /2e vary with X as 1/X.

Keldysh action of a multiterminal time-dependent scatterer

“…The pioneering works of Landauer 1 and Büttiker [2][3][4] lay the foundations for what is now known as the scattering approach to electron transport. The basic tenet is that a coherent conductor is characterized by its scattering matrix.…”

Breakdown of Interference Rules in Azulene, a Nonalternant Hydrocarbon

“…We then describe exchange and correlation effects in the GW approximation, 35,36 attach the molecules to featureless, wideband leads and calculate the transmission using the Landauer-Büttiker formula (see SI for more details). 37 The transmission curves for various substitution patterns in naphthalene and azulene are shown in Figure 4. We see first that the HOMO and LUMO transmission resonances located near -3eV and 3eV in naphthalene are symmetric about the Fermi Energy (E F ) in contrast to azulene.…”

On the Quantum Transport through an Asymmetric Aharonov-Bohm Ring with Rashba Spin-Orbit Interaction

“…. (27) This may be satisfied for certain values of AB phase and dimensionless Rashba parameter. If one takes Φ AB = 2qπ, with 0 < q < m (the parameter q must be non--integer (half integer) to obtain different spin-up and spin-down components of the conductance), the dimensionless Rashba parameter is given by the expression…”

“…[15]. At the end of this section, the transmission amplitude is analytically derived using the transfer matrix formalism [25] and the conductance is obtained, in the Landauer formalism [27]. In Sect.…”