Anomalous conductance quantization in the inter-band gap of a one-dimensional channel.

We report on a singular departure from the canonical step sequence of quantized conductance in a ballistic, quasi-one-dimensional metallic channel. Ideally in such a structure each sub-band population contributes its conductance quantum independently of the rest. In a picture based exclusively on coherent single-carrier transmission, unitary back-scattering may lower a conductance step below ideal but it is not possible for it to enhance it beyond the ideal conductance quantum.

Beyond the standard model of Ginzburg-Landau theory: multiband superconductors.

The recently discovered multiband superconductors have created a new class of novel superconductors. In these materials multiple superconducting gaps arise due to the formation of Cooper pairs on different sheets of the Fermi surfaces. An important feature of these superconductors is the interband couplings, which not only change the individual gap properties, but also create new collective modes.

Time-reversal-symmetry-broken state in the BCS formalism for a multi-band superconductor.

In three-band BCS superconductors with repulsive inter-band interactions, frustration between the bands can lead to an inherently complex gap function, arising out of a phase difference between the bands in the range 0 and π. Since the complex conjugate of this state is also a solution, the ground state is degenerate, and there appears a time-reversal-symmetry-broken state. In this paper we investigate the existence of this state as a function of inter-band coupling strength and show how a new phase transition appears between the TRSB and conventional BCS states.

Kohn singularity and Kohn anomaly in conventional superconductors--role of pairing mechanism.

We present a theoretical analysis of the Kohn singularity and Kohn anomaly in the superconducting phase of a three-dimensional metallic system. We show that a phonon mechanism-based Cooper pairing in a Fermi liquid metal can lead to these phenomena quite naturally. The results are discussed against the background of some recent experimental findings.

Nonequilibrium mesoscopic transport: a genealogy.

Models of nonequilibrium quantum transport underpin all modern electronic devices, from the largest scales to the smallest. Past simplifications such as coarse graining and bulk self-averaging served well to understand electronic materials. Such particular notions become inapplicable at mesoscopic dimensions, edging towards the truly quantum regime.

Mesoscopic transport revisited.

Having driven a large part of the decade's progress in physics, nanoelectronics is now passing from today's realm of the extraordinary to tomorrow's commonplace. This carries the problem of turning proofs of concept into practical artefacts. Better and more sharply focused predictive modelling will be the ultimate guide to optimizing mesoscopic technology as it matures.

Where is the shot noise of a quantum point contact?

Reznikov et al. [Phys. Rev.