Issue
EPL
Volume 83, Number 1, July 2008
Article Number 17004
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/83/17004
Published online 17 June 2008
EPL, 83 (2008) 17004
DOI: 10.1209/0295-5075/83/17004

Quantum pump for fractional charge

S. Das and V. Shpitalnik

Department of Condensed Matter Physics, Weizmann Institute of Science - Rehovot 76 100, Israel

sourin@wisemail.weizmann.ac.il
vadim.shpitalnik@weizmann.ac.il

received 29 December 2007; accepted in final form 5 May 2008; published July 2008
published online 17 June 2008

Abstract
We propose a theoretical scenario for pumping of fractionally charged quasi-particle in the context of $\nu$ = 1/3 fractional quantum Hall liquid. We consider quasi-particle pumping across an anti-dot level tuned close to the resonance. Fractional charge pumping is achieved by slow and periodic modulation of coupling of the anti-dot level to left and right moving edges of a Hall bar set-up. This is attained by periodically modulating the gate voltages controlling the couplings. In order to obtain quantization of pumped charge in the unit of the electronic charge fraction ($\nu$e) per pumping cycle in the adiabatic limit, we argue that the only possibility is to tune the quasi-particle operator to be irrelevant from being relevant in the renormalization group sense, which can be accomplished by invoking quantum Hall line junctions into the Hall bar geometry. We also comment on the possibility for experimental realization of the above scenario.

PACS
73.23.-b - Electronic transport in mesoscopic systems.
71.10.Pm - Fermions in reduced dimensions (anyons, composite fermions, Luttinger liquid, etc.).

© EPLA 2008