A new study may accelerate the development of quantum technologies Bashny.Net

Quantum technology can be used in a variety of areas: computers, sensors, cryptographic modeling and image processing. But the stumbling block is the need to achieve adequate reliability in terms of the control of states at the level of atoms and photons, reported Phys.org . For the preparation of a quantum system is often used to work адиабатический process , but because of its duration and the ambient noise is often a loss of "quantum state" of the system.

In order to speed up the training and minimize the декогерентность, Physicists have developed a so-called "adiabatic reduction» (STA), which is applicable to any process of transition to the quantum state. The transition itself is much faster than with the classical adiabatic process without loss of its quality and properties. This approach was originally developed for simple systems consisting of a single particle, but has recently been extended to systems of a variety of bodies that have practical application. Nevertheless, the use of STA in large systems still problematic because of the complexity of the past.

The new report, published in the journal Physical Review Letters, physicist Steve Campbell of the Royal University of Belfast, and colleagues at the University of Palermo and the National University of Singapore have developed a new method for producing a hybrid quantum states in systems including a plurality of bodies. It is optimized using the STA. The main advantage of the new method is that it allows to achieve almost perfect performance STA, which greatly simplifies the preparation of quantum states and at the same time does not require a full understanding of all the mechanisms and processes. The scientists were able to demonstrate a sufficiently low cost to reach the quantum states, coupled with high speed, which increases the attractiveness of the STA.

"Our work shows that the solution set of quantum bodies LMG-class there. This problem has attracted a lot of attention to various physical communities, studying the quantum state of the bodies, "said Campbell. "In the course of our work we were guided by the principle of" Know your enemy in the face "- an approach in which we use symmetric problems whose solution will allow us to create an effective system of quantum reduction»

As the researchers explain, the development, the quantum reduction can be compared with the search for the driver of the shortest way to work. "In a nutshell, our work can be explained by the inhabitant, even with the help of clear analogies," Campbell said. "Suppose you want to get a car from the office to work, but you do not want to stand in a traffic jam on the highway Monday morning. You will surely get to his workplace and took up his duties, but will lose a lot of time and it most likely means that you have time to do a morning only half of the planned.

As a result, you decide to cut off the path on the toll road. Yes, you pay a little bit, but you can come to your workplace on time and spend a lot less time: you have time to do all his work, your boss happy, you get a raise, and, in the end, those costs that you have incurred iz for the payment of the road do not matter »

If this project a situation where your car becomes a quantum system in a prepared state (ie is at the point of departure in your home), the quantum world, you are all well, there are two options: stand indefinitely in a traffic jam on the highway or in the general flow shortcut using quantum reduction. In terms of energy expended it will cost a bit, but will allow to realize the desired much faster.

For the situation described with a single person, a description of the problem is similar to that for the system of a single body. But Campbell said that adding more "passengers" to the stream, the situation is becoming more and more complex. Here and there is a problem for a system of many bodies.

"Now we need to crank out all the same, and to your colleagues. They all go out of their homes in the same time, all sent to the office and all face the same challenges as you, "said Campbell. "Such a situation is what we call the task for a variety of bodies. This is a serious and very difficult problem, because anyone who "leaves the office" should be "persuaded to pay a toll." It is difficult in the real world, and now imagine how difficult it is on the scale of the quantum world. While the method of quantum reduction, known as STA, solves the problem of a single object, but we know very little about the work of their sets »

Researchers have demonstrated that the method of quantum reduction (STA) may work for systems from a variety of bodies, and potentially has a huge range of application use. They believe the state must now prepare for the introduction of quantum systems in the future. The scientists plan to continue research and to reveal the true cost of "the use of toll road", that is to understand how much energy is needed for the use of STA in the set of bodies. They also plan to make the first steps towards the creation of quantum engine using STA, in which the system of many bodies will implement some previously inaccessible thermodynamic cycles.

Source: geektimes.ru/post/250204/