Electronic transmittance phase extracted from mesoscopic interferometers
Nanoscale Research Letters
Item Usage Stats
The usual experimental set-up for measuring the wave function phase shift of electrons tunneling through a quantum dot (QD) embedded in a ring (i.e., the transmittance phase) is the so-called 'open' interferometer as first proposed by Schuster et al. in 1997, in which the electrons back-scattered at source and the drain contacts are absorbed by additional leads in order to exclude multiple interference. While in this case one can conveniently use a simple two-path interference formula to extract the QD transmittance phase, the open interferometer has also a number of draw-backs, such as a reduced signal and some uncertainty regarding the effects of the extra leads. Here we present a meaningful theoretical study of the QD transmittance phase in 'closed' interferometers (i.e., connected only to source and drain leads). By putting together data from existing literature and giving some new proofs, we show both analytically and by numerical simulations that the existence of phase lapses between consecutive resonances of the 'bare' QD is related to the signs of the corresponding Fano parameters - of the QD + ring system. More precisely, if the Fano parameters have the same sign, the transmittance phase of the QD exhibits a π lapse. Therefore, closed mesoscopic interferometers can be used to address the 'universal phase lapse' problem. Moreover, the data from already existing Fano interference experiments from Kobayashi et al. in 2003 can be used to infer the phase lapses. © 2012 Tolea et al.
Phase lapse problem
Phase lapse problem
Source and drains
Published Version (Please cite this version)http://dx.doi.org/10.1186/1556-276X-7-568C
Showing items related by title, author, creator and subject.
Caglayan H.; Bulu I.; Loncar, M.; Özbay, Ekmel (Optical Society of American (OSA), 2008)In this paper, we investigated one of the promising applications of left-handed metamaterials: composite metamaterial based cavities. Four different cavity structures operating in the microwave regime were constructed, and ...
Tolea, M.; Moldoveanu, V.; Dinu, I. V.; Tanatar, Bilal (Elsevier B.V., 2012)We investigate the connection between the asymmetry of the Fano resonances in a mesoscopic interferometer with an embedded quantum dot and the π lapses in the phase of the bare dot transmittance. Consecutive Fano resonances ...
Solmaz, M. E. (Taylor and Francis, 2014)The fabrication and characterization are reported of a Fano resonance-based electro-optically tunable ring resonator-coupled Mach-Zehnder interferometer device based on a chalcogenide-lithium niobate hybrid waveguide system. ...