by josh perry, editor
[email protected]

researchers at chalmers university of technology (gothenburg, sweden) have developed a technique for manufacturing a topological superconductor, which could host majorana particles, considered a potential building block of quantum computers.

after an intensive period of analyses the research team was able to establish that they had probably succeeded in creating a topological superconductor, exciting new technology for quantum computing. (johan bodell/chalmers)

according to a report from the university, the particles are rare and are being studied as possible sources of code storage for quantum computing because of their insensitivity to decoherence, the collapse of superpositions.

in building a topological superconductor, the researchers started with a topological insulator of bismuth telluride and placed a layer of aluminum, a standard superconductor, on top. the superconducting electrons leak into the topological insulator and converts it to superconducting as well.

“however, the initial measurements all indicated that they only had standard superconductivity induced in the bi2te3 topological insulator,” the article explained. “but when they cooled the component down again later, to routinely repeat some measurements, the situation suddenly changed – the characteristics of the superconducting pairs of electrons varied in different directions.”

the team used platinum with aluminum to assemble the insulator and repeated cooling cycles produced stresses in the material that changed superconductivity into a topological superconductor.

although there are few practical applications for this technology, it could become the foundation for new quantum computers.

the research was recently published in nature communications. the abstract read:

“topological superconductivity is central to a variety of novel phenomena involving the interplay between topologically ordered phases and broken-symmetry states. the key ingredient is an unconventional order parameter, with an orbital component containing a chiral p _x  + ip _y wave term.

“here we present phase-sensitive measurements, based on the quantum interference in nanoscale josephson junctions, realized by using bi₂te₃ topological insulator. we demonstrate that the induced superconductivity is unconventional and consistent with a sign-changing order parameter, such as a chiral p _x  + ip _y component.

“the magnetic field pattern of the junctions shows a dip at zero externally applied magnetic field, which is an incontrovertible signature of the simultaneous existence of 0 and π coupling within the junction, inherent to a non trivial order parameter phase.

“the nano-textured morphology of the bi₂te₃ flakes, and the dramatic role played by thermal strain are the surprising key factors for the display of an unconventional induced order parameter.”