Superconducting Resonators: Small Current, Big Effect ⚡ экспресс
Scientists have created superconducting resonators whose frequency can be changed with tiny magnetic coils—like a radio tuning knob, but a million times more sensitive. They achieved frequency tuning of over one gigahertz using currents of millionths of an ampere. This will enable instruments capable of detecting faint magnetic signals, perhaps from the far corners of the Universe.
A superconducting circuit is like a frictionless swing, only possible at temperatures of liquid helium (–273 °C). In such cold, electric current runs in a loop without fading, keeping its rhythm. A magnetic coil, passing a tiny current, acts like a puff of air that can change the length of imaginary ropes: the rhythm shifts so sharply, as if meter-long swings turn into toy ones.
Previously, to significantly change the rhythm, large currents were required, causing heating and interference. A new approach has overcome this obstacle. Now, a current of millionths of an ampere (less than in a neuron) shifts the frequency by a billion cycles per second. This contrast turns the chip into an ultra-sensitive detector suitable for spectroscopy — precise analysis of materials — and for compact sensors in medicine and astronomy.
Engineers compared two ways of connecting the coils: air bridges and a flipped chip. Both work, but the flipped chip yields an even cleaner signal. Although the idea of controlling a superconducting circuit with a magnet is not new and underlies qubits, the achieved efficiency is record-breaking. Now fundamental principles are embodied in practical devices.
🎯 Superconducting resonators detect magnetic field fluctuations a billion times smaller than Earth's field.
🎬 This work brings quantum computers closer — devices that process information not with bits but with qubits, as in science fiction.