An international team of researchers has synthesized a unique type-I superconductor with rare quantum properties, the website infohub.kz reports.
Specialists from the Indian Institute of Science Education and Research in Bhopal (IISER Bhopal), working with foreign colleagues, produced a material that combines the characteristics of type-I superconductors with unusual quantum properties. The findings were published in the scientific journal Physical Review Letters.
The key subject of the study was ytterbium diantimonide (YbSb2). The scientists synthesized single crystals of the compound and examined their structure using X-ray analysis. The material's electrical resistance dropped to zero at a temperature of about -272 degrees Celsius, only slightly above absolute zero. Measurements of specific heat confirmed that ytterbium diantimonide is a type-I superconductor and exists in a fully gapped state with a high energy barrier.
To study the internal magnetic fields, the authors used muon spectroscopy. During the transition to the superconducting phase and in the absence of an external magnetic field, microscopic internal magnetic fields arose spontaneously in the material. This proved a violation of time-reversal symmetry — a property previously thought to belong exclusively to unconventional type-II superconductors.
Electrons in YbSb2 pair up into so-called "spin triplets," which form a net magnetic moment. The internal structure of the substance makes it possible to sustain gapless Majorana surface states. Such topological quantum materials can reliably protect quantum information from external interference, which could in the future significantly improve the architecture of quantum computers.