Dresden 2017 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Transport: Quantum Dots, Quantum Wires, Point Contacts
TT 3.8: Vortrag
Montag, 20. März 2017, 11:30–11:45, HSZ 201
Levitons in the fractional quantum Hall regime — •L. Vannucci1, F. Ronetti1,2, J. Rech2, D. Ferraro2, T. Jonckheere2, T. Martin2, and M. Sassetti1 — 1Università di Genova and CNR-SPIN, Genova, Italy — 2Aix Marseille Université, Université de Toulon, CNRS, CPT, Marseille, France
Single-electron sources are fundamental building blocks of electron quantum optics, which aims at manipulating electrons one by one in ballistic, coherent conductors. Single-particle excitations above the Fermi sea, devoid of accompanying particle-hole pairs, have been recently spotted through shot noise measurement in a quantum point contact (QPC), following the recipe provided by L. Levitov and collaborators in the '90s (hence the name `levitons' for such excitations). However, questions can be raised about the robustness of levitons against electron-electron interactions. Here we study levitons in the edge states of the fractional quantum Hall effect (FQHE), where strong Coulombian interactions give rise to exotic quasi-particles with fractional charge and statistic. It is shown that results by Levitov and coworkers are not affected by interactions, since integer levitons still represent minimal excitations states despite the highly non-linear physics occurring at the QPC due to the peculiar collective excitations of the FQHE. We use charge shot noise as well as heat and mixed correlations to shed light on the fascinating properties of Levitov's excitations. In addition, we probe them through Hong-Ou-Mandel (HOM) interferometry. The universal Pauli dip generated by HOM collisions at the QPC further demonstrates the uniqueness of levitons.