What is novel in quantum transport for mesoscopics?

MUKUNDA P DAS¹ and FREDERICK GREEN²

¹Department of Theoretical Physics, Institute of Advanced Studies,

The Australian National University, Canberra, ACT 0200, Australia

²School of Physics, The University of New South Wales,

Sydney, NSW 2052, Australia

E-mail: Mukunda.Das@anu.edu.au; mpd105@rsphy1.anu.edu.au

Abstract. The understanding of mesoscopic transport has now attained an

ultimate simplicity. Indeed, orthodox quantum kinetics would seem to

say little about mesoscopics that has not been revealed -- nearly

effortlessly -- by more popular means. Such is far from the case,

however. The fact that kinetic theory remains very much in charge is

best appreciated through the physics of a quantum point contact. While

discretization of its conductance is viewed as the exclusive result

of coherent, single-electron-wave transmission, this does not begin

to address the paramount feature of all metallic conduction: dissipation.

A perfect quantum point contact still has finite resistance, so its

ballistic carriers must dissipate the energy gained from the applied

field. How do they manage that? The key is in standard many-body

quantum theory, and its conservation principles.

Keywords. Mesoscopic systems; quantum transport; many-body kinetic theory;

conductance and noise; quantum point contacts.

PACS Nos 72.10.-d; 72.70.+m; 73.23.-b; 73.63.Nm