1. Asymmetric arms maximize visibility in hot-electron interferometers
- Author
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Masaya Kataoka, Heung-Sun Sim, Sungguen Ryu, Clive Emary, Lewis A. Clark, Clarissa J. Barratt, Engineering and Physical Sciences Research Council (UK), Ministerio de Economía y Competitividad (España), Foundation for Polish Science, European Commission, National Research Foundation of Korea, Department for Business, Energy and Industrial Strategy (UK), and European Metrology Research Programme
- Subjects
Physics ,Interferometry ,Condensed Matter - Mesoscale and Nanoscale Physics ,Quantum dot ,Wave packet ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Visibility (geometry) ,Astronomical interferometer ,FOS: Physical sciences ,Quantum Hall effect ,Interference (wave propagation) ,Quantum ,Computational physics - Abstract
We consider theoretically an electronic Mach-Zehnder interferometer constructed from quantum Hall edge channels and quantum point contacts, fed with single electrons from a dynamic quantum dot source. By considering the energy dependence of the edge-channel guide centres, we give an account of the phase averaging in this set up that is particularly relevant for the short, high-energy wavepackets injected by this type of electron source. We present both analytic and numerical results for the energy-dependent arrival time distributions of the electrons and also give an analysis of the delay times associated with the quantum point contacts and their effects on the interference patterns. A key finding is that, contrary to expectation, maximum visibility requires the interferometer arms to be different in length, with an offset of up to a micron for typical parameters. By designing interferometers that incorporate this asymmetry in their geometry, phase-averaging effects can be overcome such that visibility is only limited by other incoherent mechanisms., Comment: 12 pages; 6 figures
- Published
- 2021