A large part of quantum computers that exist today, created from superconducting qubits operating at a temperature of about 0.1 Kelvin. But to cool them spent a huge amount of energy. In the new study, researchers from the University of New South Wales together with colleagues from the universities of Keio and Aalto, as well as staff of the University of Sherbrooke created a concept of element of a quantum chip, which operates at a temperature of 1.5 Kelvin. Their work the authors published in the journal Nature. In the same issue published an article by physicists from companies QuTech and Intel, who provided a logical element based on the “hot” qubits in silicon, which proved to be reliable and manageable.
The qubit is an element of a quantum computing system in which the information is stored. An array of qubits capable of performing complex calculations, because values can be not only “0” and “1” as in a normal computer, but to stay in their superposition. But computers today are based on this technology goes beyond the walls of laboratories because of the impossibility of their use as computing systems. This is due to several factors. In particular, the transfer of information between qubits are very sensitive to different kinds of interference, from-for what the end result may be inaccurate. Besides, today, all quantum processors work on superconducting qubits, which require cooling to temperatures close to absolute zero.
Now researchers have found a way to reduce cooling costs of such systems. To do this, scientists made a few qubits in quantum dots, which in turn was placed in the silicon. This system not only demonstrated the ability to perform calculations at a temperature of 1.5 Kelvin, but it can also be created using existing industrial technology of manufacturing silicon chips. But while that’s only a couple of qubits, and the study authors are working to increase their number in the system, not reducing the working temperature.
Researchers at Intel and QuTech researched the same type of qubits based on silicon quantum dots. They were able to show that such a logical element of two qubits can be controlled. Physics did it with the help of electron spin resonance, and the reading of information was performed using Pauli spin blockade. The authors also showed that exchange interaction between two spins can be tuned with frequency 0.5 to 18 megahertz.
