Superconductivity where you don’t expect it

Topological materials keep surprising.

By applying superconducting electrodes, made of niobium, to a thin crystal flake of bismuth doped with antimony, a superconducting current flows through the material at a temperature of 10 milli Kelvin. In a superconductor, paired electrons, so-called Cooper pairs, are responsible for conduction. This is not the mechanism inside the bismuth: here, Majorana particles are responsible.
By applying superconducting electrodes, made of niobium, to a thin crystal flake of bismuth doped with antimony, a superconducting current flows through the material at a temperature of 10 milli Kelvin. In a superconductor, paired electrons, so-called Cooper pairs, are responsible for conduction. This is not the mechanism inside the bismuth: here, Majorana particles are responsible.

The special properties of ‘topological materials’ typically occur at their surface. These materials, for instance, insulators that do lead current at their surface, are expected to assume a noteworthy job in future quantum computers.

Scientists at the University of Twente in collaboration with the University of Amsterdam have demonstrated a new property: the non-superconducting material bismuth shows lossless current conduction.

It doesn’t just occur at the surface but in the inside, the bulk, of the material as well.

During this study, scientists demonstrated that the transport and spin of electrons are related, in a topological material. Due to this property, a non-superconducting material will even be able to conduct current without resistance.

Majorana ‘quasi-particles’ assume a noteworthy job in this. What makes it significantly more extraordinary: this isn’t a property that must be seen at the surface. Estimations demonstrate that superconduction likewise happens inside the material, in the ‘bulk’. This is exceptionally fascinating, as it makes the properties less vulnerable, for instance, noise or pollution.

The material that is utilized for this, bismuth with a little antimony, continues astonishing. Throughout the years, it has transformed into a ‘model material’ for electronic properties. In bismuth, the number of electrons accessible for conduction is low to the point that it can barely be known as a metal. Be that as it may, the electrons in this ‘semimetal’ do move like particles at the speed of light.

For future gadgets and quantum computing, 2D materials like graphene appear candidates. The newfound property demonstrates this doesn’t need to be a limiting factor: 3D building blocks may be conceivable too, much the same as in current-day silicon-based electronic gadgets.

The co-authors of the study include Chuan Li, Jorrit de Boer, Bob de Ronde, Shyama Ramankutty, Erik van Heumen, Yingkai Huang, Anne de Visser, Alexander Golubov, Mark Golden and Alexander Brinkman.

The study is published in the journal Nature Materials.