Robust electron pairing in the integer quantum hall effect regime

• Published in: Nature communications Vol. 6; no. 1; p. 7435
• Main Authors: Choi, H.K., Sivan, I., Rosenblatt, A., Heiblum, M., Umansky, V., Mahalu, D.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.06.2015; Nature Publishing Group
• Subjects: 639/301/119/2794; 639/766/25; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8435

Electron pairing is a rare phenomenon appearing only in a few unique physical systems; for example, superconductors and Kondo-correlated quantum dots. Here, we report on an unexpected electron pairing in the integer quantum Hall effect regime. The pairing takes place within an interfering edge channel in an electronic Fabry–Perot interferometer at a wide range of bulk filling factors, between 2 and 5. We report on three main observations: high-visibility Aharonov–Bohm conductance oscillations with magnetic flux periodicity equal to half the magnetic flux quantum; an interfering quasiparticle charge equal to twice the elementary electron charge as revealed by quantum shot noise measurements, and full dephasing of the pairs' interference by induced dephasing of the adjacent inner edge channel—a manifestation of inter-channel entanglement. Although this pairing phenomenon clearly results from inter-channel interaction, the exact mechanism that leads to electron–electron attraction within a single edge channel is not clear. We believe that substantial efforts are needed in order to clarify these intriguing and unexpected findings. Electron pairing is a rare phenomenon which can result in exotic behaviour such as superconductivity. Here, the authors evidence robust electron pairing in the quantum Hall edge states of a Fabry–Perot interferometer via Aharonov–Bohm conductance oscillations and quantum shot noise measurements.