Measurement of energy gaps in superconductors by means of quantum interference devices

Abstract

The effect of temperature on the form of discrete changes in the current in highly inductive (~10-6 H) doubly-connected superconductors with niobium-niobium clamped point contacts is determined experimentally. The magnitude and duration of the voltage pulse on a doubly-connected superconductor is measured at the time of the discrete change in its current state. The pulse magnitude is close to the energy gap 2D/e of the superconductor and its duration (~10-6 s) corresponds to the minimum possible time (~10-12 s) for a change in the state of the contact when the depairing current through it is reached. The measurement data are discussed in terms of models of the quantum interference of currents in a doubly-connected superconductor with clamped point contacts in the form of a quantum interferometer.

7 pages, 5 figures

References in corpus (3)

• Freezing and quantization of current passing through a doubly connected superconductor with a point contact
• Current states of a doubly connected superconductor with two point contacts
• Quantization of diamagnetic current in a superconducting ring with the Josephson point contact

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