The study, led by Associate Professor Saulius Vaitiekenas, demonstrates that quantum fluctuations can produce an anomalous metallic regime - a condition once thought impossible. Traditionally, superconductors conduct electricity with zero resistance, while insulators completely block current. The new state occupies a narrow window between these extremes, where conduction persists without superconductivity.
To uncover the effect, the team constructed a "switchboard" composed of nanoscale superconducting islands connected in a controllable network. By adjusting a voltage "knob" that tuned the coupling between islands, they expected the system to switch sharply from superconducting to insulating. Instead, they observed a persistent intermediate state that defied theoretical expectations.
"Our study sheds more light on this state, indicating that it's quantum fluctuations - or, to be a little more precise, the uncertainty between the superconducting phase between the islands and the number of particles in the islands within our sample - that gives rise to this behavior," said Vaitiekenas.
According to the researchers, this intermediate metallic phase reflects the delicate interplay between competing quantum orders. "Understanding such quantum phase transitions is like solving a big puzzle," Vaitiekenas added. "One piece at a time might not reveal the whole picture, but, in the long run, it might be a step toward electronics that waste less energy and quantum devices that are more controllable and reliable for future applications."
The research team included Satyaki Sasmal, Maria Efthymiou-Tsironi, Gunjan Nagda, Emma Fugl, Lara Liva Olsen, Filip Krizek, Charles M. Marcus, and Saulius Vaitiekenas.
Research Report:Voltage-Tuned Anomalous-Metal to Metal Transition in Hybrid Josephson Junction Arrays
Related Links
Niels Bohr Institutet
Space Technology News - Applications and Research
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
