quantum computer. Principle of operation

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Such machines are simply necessary now in any field: medicine, aviation, space exploration. Currently developing computers based on quantum physics and computing technologies. The basics of such a computing device are not yet available to ordinary users and are accepted as something incomprehensible. After all, not everyone is familiar with the photon properties of elementary particles and atoms. To understand at least a little how this computer works, you need to know and understand the elementary principles of quantum mechanics. For the most part, this coherent computer is being developed for NASA.

Quantum computer: principle of operation, what is it made of?

An ordinary machine performs operations using classical bits, which can take on the values ​​0 or 1. On the other hand, a photonic computing machine uses coherent bits or qubits. They can take on the values ​​1 and 0 at the same time. This is what gives such computing technology their superior computing power. There are several types of enumerative objects that can be used as qubits. 

All electrons have a magnetic field, they are usually like small magnets and this property is called spin. If they are placed in a magnetic field, they will adjust to it in the same way as a compass needle does. This is the lowest energy position, so we can call it zero or low spin. But you can redirect the electron to the "one" state or to the upper spin. But this requires energy. If you remove the glass from the compass, you can redirect the arrow in a different direction, but this requires force. 

There are two belongings: lower and upper spin, which correspond to the classical 1 and 0, respectively. But the fact is that photonic objects can be in two positions at the same time. When the spin is measured, it will be either up or down. But before the measurement, the electron will exist in the so-called quantum superposition, in which these coefficients indicate the relative probability of finding the electron in one state or another. 

It is rather difficult to imagine how this gives coherent machines their incredible computational power without considering the interaction of two qubits. Now there are four possible states of these electrons. In a typical example of two bits, only two bits of information are needed. So two qubit contains four kinds of information. So, you need to know four numbers to know the position of the system. And if you take three spins, you get eight different positions, and in a typical case, three bits will be needed. It turns out that the amount of information contained in N qubits is equal to 2N typical bits. The exponential function says that if, for example, there are 300 qubits, then you have to create crazy-complex superpositions, where all 300 qubits will be connected. Then it turns out 2300 classical bits, and this is equal to the number of particles in the entire universe. This implies, that it is required to create a logical sequence that will make it possible to obtain such a result of calculations that can be measured. That is, consisting only of standard accessories. It turns out that a coherent machine is not a replacement for conventional ones. They are faster only in calculations where it is possible to use all available superpositions. And if you just want to watch a high-quality video, chat on the Internet or write an article for work, photonicThe computer will not give you any priorities.

This video describes how a quantum computer works. 

quantum computer. What is it in simple words?

In simple words, the coherent system is not designed for the speed of calculation, but for the required amount to achieve results, which will occur in the minimum unit of time. 

The work of a classical computer is based on the processing of information using silicon chips and transistors. They use a binary code, which in turn consists of ones and zeros. The coherent machine works on the basis of superposition. Instead of bits, qubits are used. This allows not only fast, but also the most accurate calculations. 

The most powerful quantum computer in the world

What will be the most powerful photonic computing system? For example, if a photonic computer has a thirty-qubit system, then its power will be 10 trillion computational operations per second. Currently, the most powerful two-bit computer counts one billion operations per second.

A large group of scientists from different countries developed a plan according to which the dimensions of the photonic apparatus would be close to the dimensions of a football field. He will be the most powerful in the world. It will be a kind of construction of modules, which is placed in a vacuum. The interior of each module is ionized electric fields. It is with their help that certain parts of the circuit will be formed that will perform simple logical actions. An example of such a photonic computing technique is being developed at the University of Sussex in England. The estimated cost at the moment is more than 130 million dollars.

D-Wave quantum computer

Ten years ago, D-Wave introduced the world’s first coherent computer, which consists of 16 qubits. Each qubit in turn consists of a niobium crystal which is placed in an inductor. The electric current that is applied to the coil creates a magnetic field. Next, it changes the ownership that qubit is in. With the help of such a machine, it is easy to find out how synthetic drugs interact with blood proteins.
Or it will be possible to identify a disease such as cancer at an earlier stage.