Abstract
The behavior of electrons in condensed matter systems is mostly determined by the repulsive Coulomb interaction. However, under special circumstances the Coulomb interaction can be effectively attractive, giving rise to electron pairing in unconventional superconductors and specifically designed mesoscopic setups. In quantum Hall systems electron interactions can play a particularly important role due to the huge degeneracy of Landau levels, leading for instance to the emergence of quasi-particles with fractional charge and anyonic statistics. Quantum Hall Fabry-P\'erot (FPI) interferometers have attracted increasing attention due to their ability to probe such exotic physics. In addition, such interferometers are affected by electron interactions themselves in interesting ways. Recently, experimental evidence for electron pairing in a quantum Hall FPI was found (H.K. Choi et al., Nat. Comm 6, 7435 (2015)) . Theoretically describing an FPI in the limit of strong backscattering and under the influence of a screened Coulomb interaction, we compute electron shot noise and indeed find a two-fold enhanced Fano factor for some parameters, indicative of electron pairing. This result is explained in terms of an electron interaction due to exchange of neutral inter-edge plasmons, so-called neutralons.
Highlights
The quantum Hall (QH) effect is one of the most fascinating phenomena in modern condensed matter physics
It is believed that in the fractional case the elementary excitations have exotic statistics [1,2,3], such that under the spatial exchange of two quasiparticles the wave function picks up a phase factor that is different from ±1 for bosons and fermions
We have studied an integer quantum Hall interferometer with interedge coupling in the strong backscattering limit
Summary
The quantum Hall (QH) effect is one of the most fascinating phenomena in modern condensed matter physics. We propose a nonequilibrium mechanism for electron-pairing mediated by repulsive Coulomb interactions, occurring in a FPI in the integer quantum Hall regime. We consider an FPI in the presence of interedge repulsive interactions and in the strong backscattering limit, i.e., a quantum dot in the QH regime (see Fig. 1). We interpret the enhancement of the Fano factor in terms of a dynamical attraction between electrons taking place in the interfering edge via the exchange of neutralons. This example gives insight into the mechanism responsible for the enhancement of the Fano factor: A neutralon excitation left behind by one electron makes it easier for a second electron to enter the dot, and gives rise to correlated tunneling, comparable to pairing of electrons due to a retarded interaction. With the individual terms given by (4), (15), and (16)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
