Robust Electron Pairing in the Integer Quantum Hall Effect Regime

DIPC Seminars

Moty Heiblum. Weizmann Institute of Science, Rehovot, Israel
Donostia International Physics Center (DIPC). Paseo Manuel de Lardizabal, 4, Donostia
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Robust Electron Pairing in the Integer Quantum Hall Effect Regime Electron pairing is a rare phenomenon appearing only in a few unique physical systems; e.g., superconductors and Kondo-correlated quantum dots. Here, we report on an unexpected, but robust, electron "pairing" in the integer quantum Hall effect (IQHE) regime. The pairing takes place within an interfering edge channel circulating in an electronic Fabry-Perot interferometer at a wide range of bulk filling factors, 2< _ν_ _B_ <5. The main observations are: (a) High visibility Aharonov-Bohm conductance oscillations with magnetic flux periodicity Δ _ϕ_ = _φ_ 0/2= _h_ /2 _e_ (instead of the ubiquitous _h_ / _e_ ), with _e_ the electron charge and _h_ the Planck constant; (b) An interfering quasiparticle charge _e_ ∗∼2 _e_ \- revealed by quantum shot noise measurements; and (c) Full dephasing of the _h_ /2 _e_ periodicity by induced dephasing of the adjacent edge channel (while keeping the interfering edge channel intact) : a clear realization of inter-channel entanglement. While this pairing phenomenon clearly results from inter-channel interaction, the exact mechanism that leads to e-e attraction within a single edge channel is not clear.