New type of superconductivity unlocks quantum applications

Researchers in Switzerland and Italy have discovered a new type of superconductivity that could open up a range of new applications.

The research by quantum developer Terra Quantum was published in Physical Review B and describes a novel type III superconductivity that have superconducting islands separated by non-superconducting regions, resulting in unique magnetic and electrical properties. 

The Type III superconductor can reduce the energy losses in superconducting quantum qubits and cables at higher temperatures than type II materials.  

Superconductivity has been traditionally classified as type I and type II. Type I superconductors expel magnetic fields until, at a certain level of intensity of the magnetic field, superconductivity is destroyed. Type II superconductors allow magnetic fields to penetrate in some interval of magnetic fields (until superconductivity gets destroyed by high magnetic fields) in the form of so-called Abrikosov vortices containing normal cores. This implies that the motion of vortices causes finite resistance, so the practical use of type II superconductors requires the creation of special pinning mechanisms preventing vortex motion.  

One of the novel properties of the type III superconductivity is that at high magnetic fields exceeding the so-called “upper critical field.” This superconductivity gets destroyed by proliferation of vortices but not by breaking the superconducting Cooper pairs.  

• Highest performing superconducting wire segment
• Cutting the complexity of superconducting power lines
• Superconducting cables for urban electricity grid 

This opens up an opportunity for the vortices to move without energy dissipation. In usual superconductors, the motion of vortices with normal cores results in energy losses, which implies the need to introduce special vortex pinning mechanisms to ensure the practical use of superconductivity. Type III superconductivity provides movement without energy dissipation for more effective superconducting and magnetic performance.

“The unique vortex behaviour and ability to realize the superconductivity in any dimension in type III materials results in significant implications for the practical use of superconductivity,” said Terra Quantum’s Chief Scientific Officer Valerii Vinokur. The Type III superconductors do not have normal cores and move without creating any resistance, he says. This means that type III superconductors keep their superconducting properties even in the applied magnetic fields, and there is no need to create a special pinning mechanism for vortices, which is a good practical problem in usual type II superconductors. This would allow superconducting qubits that work without power losses.

New phenomena, including the creation of the electric Coulomb fields by moving novel vortices, require careful further investigation.

“As we develop useful applications for quantum computing, we’re excited to see how our work in superconducting technology will improve quantum technologies and the electronics industry altogether,” said Markus Pflitsch, CEO of Terra Quantum.  

The research, “Topological gauge theory of vortices in type-III superconductors,” was published in Physical Review B, and presents a new theory describing the superconductors. The paper was co-authored by Terra Quantum’s Chief Scientific Officer Valerii Vinokur, Cristina Diamantini at the University of Peruglia, Italy, and Carlo Trugenberger at SwissScientific.