Lancaster scientists have shown that other physicists’ recent “discovery” of the field effect in superconductors is nothing but hot electrons after all.
A team of scientists from Lancaster’s physics department have found new and compelling evidence that the observation of the field effect in superconducting metals by another group can be explained by a simple mechanism involving the injection of electrons, without the need for new physics.
Dr Sergey Kafanov, who initiated this experiment, said: “Our results unambiguously refute the claim of the electrostatic field effect claimed by the other group. This brings us back to the field and helps maintain the health of the group. discipline.”
The experimental team also includes Ilia Golokolenov, Andrew Guthrie, Yuri Pashkin and Viktor Tsepelin.
Their work is published in the latest issue of Nature communications.
When certain metals are cooled to a few degrees above absolute zero, their electrical resistance disappears – a striking physical phenomenon known as superconductivity. Many metals, including vanadium, which was used in the experiment, are known to exhibit superconductivity at sufficiently low temperatures.
For decades, it was believed that the unusually low electrical resistance of superconductors should make them virtually impervious to static electric fields, due to the way that charge carriers can easily organize themselves to compensate for any external field.
So it came as a shock to the physics community when a number of recent publications claimed that sufficiently strong electrostatic fields could affect superconductors in nanoscale structures – and attempted to explain this new effect with a new corresponding physics. A related effect is well known in semiconductors and underlies the entire semiconductor industry.
Lancaster’s team integrated a similar nanometric device into a microwave cavity, allowing them to study the presumed electrostatic phenomenon at much shorter timescales than those previously studied. Over short timescales, the team saw a marked increase in noise and energy loss in the cavity – properties strongly associated with device temperature. They propose that under intense electric fields, high energy electrons can “jump” into the superconductor, raising the temperature and therefore increasing dissipation.
This simple phenomenon can concisely explain the origin of the “electrostatic field effect” in nanoscale structures, without any new physics.
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