Physicists from Britain and Russia created a detector of quantum States

© Photo : press service of MIPT/Eugene Plaindealer quantum States created in physics from MIPT and BritainPhysicists from Britain and Russia created a detector of quantum States© Photo : press service of MIPT/Evgeniy Pelevin

. Scientists from MIPT and the UK turned a set of several pieces of superconductor in ultra-sensitive sensor of magnetic fields and detector of quantum States that can be used to create quantum computers, says the article, published in the journal Nano Letters.

«Our technology is surprisingly simple, we take in General it is usual for superconductivity material and use the long-known methods of fabrication such as electron-beam lithography and high vacuum evaporation of aluminum. But in the end, we get a system that until now nobody ever studied,» says Vladimir Gurtovoy, a physicist from MIPT, whose word brings the press service of the University.

About half a century ago, many scientists believed that the laws of quantum physics can only influence the behavior of the microcosm objects which we cannot see with our own eyes. This misconception was refuted in that moment, when scientists began to observe what happens inside the rings of superconductor, torn at one point and separated by a thin insulating layer.

Initially, physicists believed that the movement of the superconducting current will cease after this operation or significantly reduced, however, the experiments showed that it is not – the electrons begin to jump from one end of the conductor to another through quantum tunneling. How many electrons can simultaneously pass through the barrier depends on the strength of the magnetic fields and many other factors.

The existence of this phenomenon was predicted by the British physicist Brian Josephson (Brian Josephson) in 1962 for this discovery he received the Nobel prize in physics in 1973. Today, the transitions of Josephson actively used to create highly sensitive sensors of magnetic fields and as a basic cell of quantum computers, but also in determining many physical quantities.

Gurtovoy and his colleagues have created a new quantum device on the basis of Josephson transitions, is able to detect the quantum state in passing through it currents and thus react more strongly to magnetic fields than conventional superconducting sensors, so-called squids, operating on the basis of the same effect but are more sensitive to interference and with certain other drawbacks.

It consists of two diamond rings from superconducting materials, which are embedded in two such «gap», located in such a way that the whole structure begins to very rapidly respond to changes in the quantum States of currents that took place simultaneously in both directions through one of these rings.

This allows the use of such a device not only as a replacement for conventional squids, but also as a device enabling to accurately read data from superconducting qubits, the basic computational cell of quantum computers. It is enough to replace one of the superconducting rings for the qubit. As scientists hope that their detector quantum States will accelerate the development of such computers.

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