Normal metal - insulator - superconductor interferometer

Abstract

Hybrid normal metal - insulator - superconductor microstructures suitable for studying an interference of electrons were fabricated. The structures consist of a superconducting loop connected to a normal metal electrode through a tunnel barrier . An optical interferometer with a beam splitter can be considered as a classical analogue for this system. All measurements were performed at temperatures well below 1 K. The interference can be observed as periodic oscillations of the tunnel current (voltage) through the junction at fixed bias voltage (current) as a function of a perpendicular magnetic field. The magnitude of the oscillations depends on the bias point. It reaches a maximum at energy $eV$ which is close to the superconducting gap and decreases with an increase of temperature. Surprisingly, the period of the oscillations in units of magnetic flux $\Delta \Phi$ is equal neither to $h/e$ nor to $h/2e$, but significantly exceeds these values for larger loop circumferences. The origin of the phenomena is not clear.

11 pages and 8 figures

References in corpus (6)

• Density of states in a superconductor carrying a supercurrent
• Multiple flux jumps and irreversible behavior of thin Al superconducting rings
• Dilation of the Giant Vortex State in a Mesoscopic Superconducting Loop
• Dynamic transitions between metastable states in a superconducting ring
• Non-Linear and Non-Local Meissner Effect in Superconducting Wires
• Nucleation of Superconductivity in a Mesoscopic Loop of Finite Width

Cited by in corpus (10)

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• Weber blockade theory of magnetoresistance oscillations in superconducting strips
• Microscopic model for multiple flux transitions in mesoscopic superconducting loops
• Quasi-1-Dimensional Superconductivity in Highly Disordered NbN Nanowires
• Local superfluid densities probed via current-induced superconducting phase gradients
• Fabrication and characterization of vacuum deposited fluorescein thin films
• Particle renormalizations in presence of dissipative environments
• The stationary SQUID
• Tunneling spectroscopy of persistent currents in superconducting microrings