in magazines Nature And Science A group of scientists from the University of Washington reported the discovery of signs of theoretically promising topological qubits – anions (not to be confused with anions). At one time, the Russian physicist Oleksiy Kitaev proposed using topological quantum calculations and enions as qubits, but the practical or even experimental application of these possibilities did not work. A new discovery promises to help with this.

In general, topological quantum computing involves the use of topological qubits, which differ from ordinary qubits in their very high resistance to external interference. This means that a quantum system will be error-free even if there are enough qubits in the system. Kitaev proposed two-dimensional topological phases with anions in which the fractional quantum anomalous Hall (FQAH) effect was observed as topological qubits.

And now American scientists have reported that the signs of the small Hall effect have been reliably detected. The discovery marks a promising first step in creating a fault-tolerant qubit, because FQAH states can contain enions, which are strange “half-particles” that only have a fraction of an electron’s charge. Some types of anions, as predicted by Chinav, can be used to form so-called “topologically conserved” qubits that are resistant to any small local perturbation.

“This really sets up a new paradigm for the future study of quantum physics with small excitations.” Said Xiaodong Xu, the paper’s lead author and also a Boeing Distinguished Professor of Physics and Professor of Materials Science and Engineering at the University of Washington.

The scientists were able to achieve the indicated effect when setting up an experiment with two “scales” of a two-dimensional semiconductor material such as molybdenum tellurium (MoTe). ₂ ). One atom-thick plate was placed one on top of the other and slightly rotated so that the atomic lattices formed a moire. As a result, the electrons were arranged in a structure that recreated a new exotic form of matter with its own properties.

For example, the structure showed magnetism without the application of an external magnetic field. And if, under normal conditions, the appearance of the quantum Hall effect requires the strongest magnetic fields, which puts an end to the practical value of the phenomenon, then in the new state of matter, internal magnetism has caused this effect to appear, giving rise to anions (“dividing” the charge of the interacting electrons into fractions of stable particles). ). From this arises the stability of qubits and the possibility of bound or entangled states – all that is required for stable quantum computing.

Moreover, the proposed platform promises to aid the study of other equally exotic quasiparticles proposed by Kitaev as candidates for topological qubits – non-Abelian enions.

“This kind of topological qubit will be fundamentally different from any that can currently be created, University of Washington physics doctoral student Eric Anderson is lead author of the paper in Science and co-author of the paper in Nature. — The strange behavior of non-Abelian anions would make them much more reliable as a platform for quantum computing.”