Fractional ac Josephson effect in unconventional superconductors

Abstract

For certain orientations of Josephson junctions between two p_x-wave or two d-wave superconductors, the subgap Andreev bound states produce a 4pi-periodic relation between the Josephson current I and the phase difference phi: I ~ sin(phi/2). Consequently, the ac Josephson current has the fractional frequency eV/h, where V is the dc voltage. In the tunneling limit, the Josephson current is proportional to the first power (not square) of the electron tunneling amplitude. Thus, the Josephson current between unconventional superconductors is carried by single electrons, rather than by Cooper pairs. The fractional ac Josephson effect can be observed experimentally by measuring frequency spectrum of microwave radiation from the junction.

8 pages, 3 figures, RevTEX 4; v2. - minor typos corrected in proofs

Cited by in corpus (19)

• Majorana Fermions in Chiral Topological Ferromagnetic Nanowires
• Mutation of Andreev into Majorana bound states in long NS and SNS junctions
• Floquet Majorana zero and $\pi$ modes in planar Josephson junctions
• Thermopower of three-terminal topological superconducting systems
• Josephson effect in superconducting wires supporting multiple Majorana edge states
• Majorana bound states in encapsulated bilayer graphene
• Suppression of 2π phase-slip due to hidden zero modes in one dimensional topological superconductors
• Effects of finite superconducting coherence lengths and of phase gradients in topological SN and SNS junctions and rings
• Chiral current-phase relation of topological Josephson junctions: A signature of the $4\pi$-periodic Josephson effect
• Multiple Andreev reflections in topological insulator nanoribbons
• Nonequilibrium Andreev bound states population in short superconducting junctions coupled to a resonator
• A particle conserving approach to AC-DC driven interacting quantum dots with superconducting leads
• Photonic cross-noise spectroscopy of Majorana bound states
• Quasiparticle poisoning in trivial and topological Josephson junctions
• Probing Majorana bound states via a pn-junction containing a quantum dot
• Atomistic modeling of a superconductor-transition-metal dichalcogenide-superconductor Josephson junction
• Magnetic exchange interaction in spin-valve with chiral spin-triplet superconductor
• Tunable effective length of fractional Josephson junctions
• Giant and robust Josephson diode effect in multiband topological nanowires