The revolutionary proposal of Russian scientists on the draft quantum computer
Physicists from the Moscow University of Physics and Technology, as well as MISiS and other universities presented an alternative to the electromagnetic basis of the quantum computer (QC). Together with colleagues from Britain, the principle of operation of a quantum system was developed in which the data storage element in QC (the so-called qubit) interacts not with electromagnetic waves, but with acoustic waves. We are talking about the interaction in a specially created resonator.
Scientists note that the possibility of interaction along the line "elements of quantum optics - elements of acoustics" can be used in the future to develop ideas related to the implementation of an ambitious project of a quantum computer. It is stated that the acoustic approach to the project implementation has a number of advantages over the exclusively quantum QC model, which has been used up to this point.
What is the essence of the proposal? It lies in the fact that the working chip is presented in the form of a quartz piezoelectric base with a deposition of an aluminum circuit and the so-called transmon.
For reference: Transmon is a type of superconducting charge qubit designed to reduce the charge effect “noise” sensitivity. The transmon achieves its reduced sensitivity to charge noise, significantly increasing the ratio of Josephson energy to charging energy. This is achieved through the use of a large capacity shunt capacitor. The concept was developed by American scientists in 2007 year.
In addition, the circuit includes a radiator, a receiver, and the aforementioned resonator, consisting of a pair of mirrors reflecting waves of a certain length.
Acoustic waves running from mirror to mirror in the resonator, thus occur on the surface of the solid-state base.
The whole structure is cooled in a cryostat to a temperature that tends to absolute zero (up to several mK - milliCelvin). This raises questions from the point of view of the parameters of the use of QC in normal conditions.
A transmon with two energy levels, between which the transitions take place, in this situation demonstrates the behavior characteristic of the atom. Thus, scientists say they have received an artificial version of an atom that can be controlled. Management is associated with the ability to transfer energy to the qubit, putting the system into a state of "quantum excitation". Then, controlled radiation of energy can be carried out with a certain frequency. Thus, it will be possible to read information from the qubit by taking into account the characteristics of the waves in the resonator.
With all the seemingly scientific breakthrough with quantum computers, the quantum concept has its Achilles heel. It is connected with the size of the resonator. The larger the dimensions of the resonator, the greater the defects on the surface of the crystal used. However, the new discovery allows, as Russian and British scientists believe, to create a resonator of high homogeneity with dimensions of several hundred micrometers - this is substantially less than a system in which only quantum principles are used. And accordingly, the reserve and memory performance is also higher. On the other hand, the problem is in the speed of propagation of the sound wave, which is known to be more than significantly lower than the light one. But still, experts note that a quantum computer may turn out to be “quantum acoustic” in the end, taking into account all the advantages of the two principles of operation.
- wikipedia.org, https://journals.aps.org
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