Abstract

The pairing of electrons is ubiquitous in electronic systems featuring attractive inter-electron interactions, as exemplified in superconductors. Counter-intuitively, it can also be mediated in certain circumstances by the repulsive Coulomb interaction alone. Quantum Hall Fabry-Pérot interferometers tailored in two-dimensional electron gas under a perpendicular magnetic field have been argued to exhibit such unusual electron pairing seemingly without attractive interactions. Here, we show evidence in graphene quantum Hall Fabry-Pérot interferometers revealing not only a similar electron pairing at bulk filling factor νB = 2 but also an unforeseen emergence of electron tripling characterized by a fractional Aharonov-Bohm flux period h/3e at νB = 3. Leveraging novel plunger-gate spectroscopy, we demonstrate that electron pairing (tripling) involves correlated charge transport on two (three) entangled QH edge channels.

Abstract

The pairing of electrons is ubiquitous in electronic systems featuring attractive inter-electron interactions, as exemplified in superconductors. Counter-intuitively, it can also be mediated in certain circumstances by the repulsive Coulomb interaction alone. Quantum Hall Fabry-Pérot interferometers tailored in two-dimensional electron gas under a perpendicular magnetic field have been argued to exhibit such unusual electron pairing seemingly without attractive interactions. Here, we show evidence in graphene quantum Hall Fabry-Pérot interferometers revealing not only a similar electron pairing at bulk filling factor νB = 2 but also an unforeseen emergence of electron tripling characterized by a fractional Aharonov-Bohm flux period h/3e at νB = 3. Leveraging novel plunger-gate spectroscopy, we demonstrate that electron pairing (tripling) involves correlated charge transport on two (three) entangled QH edge channels.

Abstract

The pairing of electrons is ubiquitous in electronic systems featuring attractive inter-electron interactions, as exemplified in superconductors. Counter-intuitively, it can also be mediated in certain circumstances by the repulsive Coulomb interaction alone. Quantum Hall Fabry-Pérot interferometers tailored in two-dimensional electron gas under a perpendicular magnetic field have been argued to exhibit such unusual electron pairing seemingly without attractive interactions. Here, we show evidence in graphene quantum Hall Fabry-Pérot interferometers revealing not only a similar electron pairing at bulk filling factor νB = 2 but also an unforeseen emergence of electron tripling characterized by a fractional Aharonov-Bohm flux period h/3e at νB = 3. Leveraging novel plunger-gate spectroscopy, we demonstrate that electron pairing (tripling) involves correlated charge transport on two (three) entangled QH edge channels.

Abstract

The pairing of electrons is ubiquitous in electronic systems featuring attractive inter-electron interactions, as exemplified in superconductors. Counter-intuitively, it can also be mediated in certain circumstances by the repulsive Coulomb interaction alone. Quantum Hall Fabry-Pérot interferometers tailored in two-dimensional electron gas under a perpendicular magnetic field have been argued to exhibit such unusual electron pairing seemingly without attractive interactions. Here, we show evidence in graphene quantum Hall Fabry-Pérot interferometers revealing not only a similar electron pairing at bulk filling factor νB = 2 but also an unforeseen emergence of electron tripling characterized by a fractional Aharonov-Bohm flux period h/3e at νB = 3. Leveraging novel plunger-gate spectroscopy, we demonstrate that electron pairing (tripling) involves correlated charge transport on two (three) entangled QH edge channels.