Superconductivity is continually revolutionizing technology in numerous ways. While some technological advancements focus on enabling zero-resistance currents at higher temperatures, engineers are also exploring better methods to precisely control the super-efficient electron flow.
Unfortunately, many techniques suitable for ordinary electronics, like the use of external magnetic fields, risk compromising the properties that make superconductors so effective.
An international team of scientists has managed to confine an exotic state of superconductivity that is influenced by strong magnetism instead of being disrupted by it.
In this breakthrough, the researchers utilized a topological insulator—a semiconductor material that conducts electricity on its surface but not internally, due to the specific arrangement of its electrons.
“What’s exciting is that we can integrate magnetic atoms into topological insulators so they can be manipulated by magnets,” explains physicist Charles Gould, from the University of Würzburg in Germany.
The team developed a two-dimensional topological insulator using mercury, manganese, and tellurium. This composition enabled them to prompt electrons into an exotic configuration known as the proximity-induced Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, where the quantum-assisted electron pairings that allow for resistance-free current flow are modified to allow control.
This setup could function as a Josephson junction, a critical element in superconducting circuits that separates superconducting sections with a thin layer of non-superconducting material.
While the FFLO state has previously been observed in superconducting materials as a bulk property, confining it within a Josephson junction for controlled manipulation allows physicists to examine the phenomenon more closely and to develop technologies that might better manage superconducting systems.
“We merge the benefits of a superconductor with the controllability provided by the topological insulator,” Gould notes.
“With an external magnetic field, we now have the capability to precisely adjust the superconducting properties. This represents a significant breakthrough in quantum physics.”
As always, a deeper comprehension of physical phenomena, like the interaction between superconductivity and magnetism, could lead to more innovative applications.
Superconductivity is already employed in various applications, from components in MRI (Magnetic Resonance Imaging) machines to maglev trains that hover above the tracks—another demonstration of the dynamic relationship between superconductors and magnets.
Looking ahead, the insights from this study might pave the way for developing superconductors that are finely tuned for specific tasks and purposes. One potential application mentioned by the researchers is in quantum computing, where controlling electrons and minimizing interference from external sources are vital for functionality.
“The issue is that quantum bits are currently very unstable because they’re highly susceptible to external influences like electric or magnetic fields,” Gould mentions.
“Our findings could potentially stabilize quantum bits, making them viable for use in future quantum computers.”
This research has been published in Nature Physics.
