Nonequilibrium noise as a probe of pair-tunneling transport in the BCS--BEC Crossover

Abstract

The detection of elementary carriers in transport phenomena is one of the most important keys to understand non-trivial properties of strongly-correlated quantum matter. Here we propose a method to identify the tunneling current carrier in strongly interacting fermions from nonequilibrium noise in the Bardeen-Cooper-Schrieffer to Bose--Einstein condensate crossover. The noise-to-current ratio, the Fano factor, can be a crucial probe for the current carrier. Bringing strongly-correlated fermions into contact with a dilute reservoir produces a tunneling current in between. The associated Fano factor increases from one to two as the interaction becomes stronger, reflecting the fact that the dominant conduction channel changes from the quasiparticle tunneling to the pair tunneling.

7+7 pages, 4+2 figures

References in corpus (19)

• Many-Body Physics with Ultracold Gases
• Tunable Phase Boundaries and Ultra-Strong Coupling Superconductivity in Mirror Symmetric Magic-Angle Trilayer Graphene
• Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
• Roadmap on Atomtronics: State of the art and perspective
• Gate-controlled BCS-BEC crossover in a two-dimensional superconductor
• Two-electron bunching in transport through a QD induced by Kondo correlations
• Electron pairing in the pseudogap state revealed by shot noise in copper-oxide junctions
• Quantum vortex core and missing pseudogap in the multi-band BCS-BEC-crossover superconductor FeSe
• Spin current noise of the spin Seebeck effect and spin pumping
• Macroscopic Periodic Tunneling of Fermi Atoms in the BCS-BEC Crossover
• Direct evidence for Cooper pairing without a spectral gap in a disordered superconductor above $T_C$
• Tunneling transport of unitary fermions across the superfluid transition
• Anomalous conductances in an ultracold quantum wire
• High-temperature limit of the resonant Fermi gas
• Anomalous Conductance of a strongly interacting Fermi Gas through a Quantum Point Contact
• Interaction-Assisted Reversal of Thermopower with Ultracold Atoms
• Josephson effect at finite temperature along the BCS-BEC crossover
• Multi-Particle Tunneling Transport at Strongly-Correlated Interfaces
• Noise in tunneling spin current across coupled quantum spin chains

Cited by in corpus (4)

• Probing Goldstino excitation through the tunneling transport in a Bose-Fermi mixture with explicitly broken supersymmetry
• Spin transport between polarized Fermi gases near the ferromagnetic phase transition
• Magnonic spin current shot noise in an itinerant Fermi gas
• Schwinger-Keldysh approach to tunneling transport at a hadron-quark interface