"Quanta" here and now (part 1)
I think this topic may interest a lot of people, because lately it has become quite popular, and most importantly relevant. Well, and in order not to rant into an empty one, I will immediately indicate the direction of my scrolls. The main topics of my reasoning and, ideally, discussions with you, I would like to indicate such areas as quantum communication and quantum computing .
But, before discussing such things, I would like to receive from you any information about what you personally would have liked to begin with. In my opinion, any conversation about quantum things of any kind should begin with a statement of the basic tenets of quantum physics , but not in a form that is often presented in Russian schools and universities, and in a somewhat different, more intuitive. All that is required from you, in my opinion, is purely fantasy and the presence of at least some ideas about the world around, well, of course, it does not hurt at least some kind of built-in logic. However, I have not the slightest doubt that the readers of this portal have all this present with interest. So, perhaps, let's start.
But I still prefer to start not quite from this. First of all, I would like to raise the issue of relevance. Why is all this necessary? Some kind of quantum communications, quantum computations, whether they are three times wrong, as if classical ones no longer fit. What is it? Why is this? Why does modern society pay so much attention to this? The answer to madness is simple - such hype around quantum things is caused by two main advantages: a much higher speed with the highest computing power and, of course, absolute secrecy and the safety of your personal data. And, it should be noted, a significant part of the interest of the modern world community attracts the opportunity to leave your data unread, absolutely secret . And here the conversation is not at all about some kind of secrecy, due to the allegedly insufficient power of modern devices, namely, the fundamental, absolute secrecy, which follows from the fundamental principles of quantum mechanics. This opens up radically new opportunities for their owner, beyond the control of the “mere mortal”.
')
But, it should be noted, everything is not so simple, this question is nothing but a double-edged sword, in fact, like everything else in this world. Already starting from here, it is possible to trace how quantum mechanics intervenes in our reasoning. Already here we are confronted with such a concept as superposition . In this case, it is a superposition of good and bad. Of course, this is an absolutely philosophical question, but here I am forced to note that physics and philosophy have always been inextricably linked with each other. So back, perhaps to the superposition. Of course, absolute confidentiality is the dream of so many people in this world, besides, many companies, if not all, army-related structures and banks are ready to sell for the inability to hack their data almost soul. And here I propose to think about this: is absolute secrecy so good as it seems at first glance? I will leave this question solely for your consideration and suggest that everyone decide for themselves how to relate to this.
I would like to note that I personally relate to this issue solely from the side of a research scientist, and I would like to sometime reach an understanding, albeit in theory, how this should work and how to come to replace the usual ones for us Now, communication systems are quantum. And, therefore, in my further narrative, I will stick to this point of view, perhaps, I emphasize, perhaps , periodically moving towards philosophical reflections, but I will try to resort to this as rarely as possible.
Just do not forget about quantum computing. I would like to devote the first part of my articles to them, highlighting in them the basic concepts of quantum informatics mixed with the necessary mathematical knowledge. I will try to make this presentation as accessible as possible so that all information is available even to people without any training in the field of informatics and physics. You can ask a reasonable question - why is this necessary and what is the benefit from it? I will try to briefly answer your questions. In the field of quantum information and quantum computing, information processing tasks are being studied, which, as you can guess, can be implemented and performed using quantum-mechanical schemes. Logical and simple, isn't it? But, as is usually the case, throughout the entire history of the development of science, a rather long period of time elapsed before scientists came to this. In order to understand why everything was so, it would not be superfluous to consider each of the areas that contributed to the development of this area: computer science, quantum mechanics, information theory, linear algebra, and, of course, cryptography. It will be quite difficult to do, but I will try to present this most interesting and fascinating.
It all started with the fact that in physics at the end of the XIX century a significant crisis of ideas arose, leading to a large number of paradoxes. In view of the current situation, it was necessary to find a solution to this problem. Initially, it was an introduction to classical physics of separate special hypotheses, but, with an improved understanding of many properties of atoms and radiation, by the 20s of the 20th century, the necessary critical mass of knowledge had been accumulated to create a new theory. She became quantum mechanics, which was successfully used to describe all sorts of objects and phenomena. So what is quantum mechanics? Quantum mechanics is nothing more than a mathematical apparatus used to construct a physical theory. Roughly speaking, it is a kind of crutch necessary for building a beautiful and slim theory. Its principles are simple enough, but even leading experts find them to contradict ordinary human intuition. This is evidenced by the views of many of the founders of this trend, who could not come to terms with it, get used to the fact that they also invented. The origins of quantum information and quantum computing can, if desired, be seen just in the desire of physicists to better understand quantum mechanics and adapt its predictions to human intuition.
Just one of the objectives of this direction is to find a toolkit that would help make the understanding of quantum mechanics more intuitive, and not contrary to our traditional ideas about the world. It’s much more difficult for us and you to do this, because we started to lay a much more approximate and already outdated understanding of the world in school, and ideally we should try to build a different way from the very beginning, I personally see the solution to this.
For example, in the early 80s. Scientists began to wonder whether quantum effects could be used to transmit a signal faster than the speed of light, contrary to Einstein's theory. The solution to this problem came down to the fact that it was necessary to understand whether it was possible to copy an unknown quantum state. If this turned out to be quite possible, then it would be possible to transmit information much faster than the speed of light. It was then that the theorem on the impossibility of cloning appeared . For classical information, copying is a rather simple and ordinary operation, while in quantum mechanics, in general, this turns out to be impossible.
In addition, another direction of research has made a significant contribution to this direction, which appeared in the 70s. interest in gaining complete control over single quantum systems . Prior to this, control was usually carried out on bulk samples containing a huge number of quantum mechanical systems, moreover, none was directly available. Elementary particle accelerators came to the aid of scientists, who helped to get limited access to this most notorious control of individual systems, but it is still was incomplete.
In order to control single quantum-mechanical systems, a large number of methods were subsequently developed that allow one to learn many new aspects of the behavior of such systems.
So why all these delights and tricks in the direction of achieving control over such systems? If we discard various technological reasons and leave only scientific ones, the answer will be ridiculously simple - the researchers proceeded from intuitive considerations. In science, often many significant discoveries are made when a sufficient mass of results accumulates in a new field of research. So now we are only taking the first steps in mastering this, but have already managed to get some interesting and unexpected results. So what can we expect when we still learn to fully control individual quantum-mechanical systems and transfer these algorithms and understanding to the control of the ensembles of such systems?
Just the direction of quantum computing and quantum information theory pushes us to search for new ways to manage these systems and search for opportunities to apply the knowledge gained.
And, unfortunately, despite all the efforts and popularity of this area, the results that we have today are rather scant. Modern technology is represented only by small quantum computers with a limited number of quantum bits ( qubits ), as well as some optical quantum circuits. There are even implementations of quantum cryptographic systems capable of making data transmission over long distances with absolute secrecy, but at the moment these are only prototypes of the necessary systems. Nevertheless, even they can now they can be quite useful in some practical specialized applications.
Let's go back to the original questions. What awaits us in the future? What is so special about quantum computing and quantum information that science, technology, and all of humanity can offer? What are the main problems that need to be addressed? Quantum computing and quantum information taught us to think about computing physically, so we found a huge amount of new opportunities in the field of communication and information processing. Of course, these areas pose a lot of tasks for physicists and engineers, and it is not entirely clear what this will lead to in the long term. Quantum computing and quantum information provide new opportunities that allow you to move from simpler to more complex. In addition, the ideas of these areas allow us to form new views on physics, which is equally important.
In the proposed article, some key goals, motivations that underlie these areas of interest were briefly and briefly reviewed. In addition, I tried to give a very short historical excursion on the part of physics, showing a part of the prehistory that led to the appearance of quantum computing and quantum information theory. In addition to physics, it would not hurt to consider, as I have already said, the history of computer science, information theory and cryptography. All this I leave for the following articles, if it arouses someone’s interest. And today, perhaps, everything.
Thanks for attention!
But, before discussing such things, I would like to receive from you any information about what you personally would have liked to begin with. In my opinion, any conversation about quantum things of any kind should begin with a statement of the basic tenets of quantum physics , but not in a form that is often presented in Russian schools and universities, and in a somewhat different, more intuitive. All that is required from you, in my opinion, is purely fantasy and the presence of at least some ideas about the world around, well, of course, it does not hurt at least some kind of built-in logic. However, I have not the slightest doubt that the readers of this portal have all this present with interest. So, perhaps, let's start.
Relevance.
But I still prefer to start not quite from this. First of all, I would like to raise the issue of relevance. Why is all this necessary? Some kind of quantum communications, quantum computations, whether they are three times wrong, as if classical ones no longer fit. What is it? Why is this? Why does modern society pay so much attention to this? The answer to madness is simple - such hype around quantum things is caused by two main advantages: a much higher speed with the highest computing power and, of course, absolute secrecy and the safety of your personal data. And, it should be noted, a significant part of the interest of the modern world community attracts the opportunity to leave your data unread, absolutely secret . And here the conversation is not at all about some kind of secrecy, due to the allegedly insufficient power of modern devices, namely, the fundamental, absolute secrecy, which follows from the fundamental principles of quantum mechanics. This opens up radically new opportunities for their owner, beyond the control of the “mere mortal”.
')
But, it should be noted, everything is not so simple, this question is nothing but a double-edged sword, in fact, like everything else in this world. Already starting from here, it is possible to trace how quantum mechanics intervenes in our reasoning. Already here we are confronted with such a concept as superposition . In this case, it is a superposition of good and bad. Of course, this is an absolutely philosophical question, but here I am forced to note that physics and philosophy have always been inextricably linked with each other. So back, perhaps to the superposition. Of course, absolute confidentiality is the dream of so many people in this world, besides, many companies, if not all, army-related structures and banks are ready to sell for the inability to hack their data almost soul. And here I propose to think about this: is absolute secrecy so good as it seems at first glance? I will leave this question solely for your consideration and suggest that everyone decide for themselves how to relate to this.
I would like to note that I personally relate to this issue solely from the side of a research scientist, and I would like to sometime reach an understanding, albeit in theory, how this should work and how to come to replace the usual ones for us Now, communication systems are quantum. And, therefore, in my further narrative, I will stick to this point of view, perhaps, I emphasize, perhaps , periodically moving towards philosophical reflections, but I will try to resort to this as rarely as possible.
Prerequisites in quantum mechanics.
Just do not forget about quantum computing. I would like to devote the first part of my articles to them, highlighting in them the basic concepts of quantum informatics mixed with the necessary mathematical knowledge. I will try to make this presentation as accessible as possible so that all information is available even to people without any training in the field of informatics and physics. You can ask a reasonable question - why is this necessary and what is the benefit from it? I will try to briefly answer your questions. In the field of quantum information and quantum computing, information processing tasks are being studied, which, as you can guess, can be implemented and performed using quantum-mechanical schemes. Logical and simple, isn't it? But, as is usually the case, throughout the entire history of the development of science, a rather long period of time elapsed before scientists came to this. In order to understand why everything was so, it would not be superfluous to consider each of the areas that contributed to the development of this area: computer science, quantum mechanics, information theory, linear algebra, and, of course, cryptography. It will be quite difficult to do, but I will try to present this most interesting and fascinating.
It all started with the fact that in physics at the end of the XIX century a significant crisis of ideas arose, leading to a large number of paradoxes. In view of the current situation, it was necessary to find a solution to this problem. Initially, it was an introduction to classical physics of separate special hypotheses, but, with an improved understanding of many properties of atoms and radiation, by the 20s of the 20th century, the necessary critical mass of knowledge had been accumulated to create a new theory. She became quantum mechanics, which was successfully used to describe all sorts of objects and phenomena. So what is quantum mechanics? Quantum mechanics is nothing more than a mathematical apparatus used to construct a physical theory. Roughly speaking, it is a kind of crutch necessary for building a beautiful and slim theory. Its principles are simple enough, but even leading experts find them to contradict ordinary human intuition. This is evidenced by the views of many of the founders of this trend, who could not come to terms with it, get used to the fact that they also invented. The origins of quantum information and quantum computing can, if desired, be seen just in the desire of physicists to better understand quantum mechanics and adapt its predictions to human intuition.
Just one of the objectives of this direction is to find a toolkit that would help make the understanding of quantum mechanics more intuitive, and not contrary to our traditional ideas about the world. It’s much more difficult for us and you to do this, because we started to lay a much more approximate and already outdated understanding of the world in school, and ideally we should try to build a different way from the very beginning, I personally see the solution to this.
For example, in the early 80s. Scientists began to wonder whether quantum effects could be used to transmit a signal faster than the speed of light, contrary to Einstein's theory. The solution to this problem came down to the fact that it was necessary to understand whether it was possible to copy an unknown quantum state. If this turned out to be quite possible, then it would be possible to transmit information much faster than the speed of light. It was then that the theorem on the impossibility of cloning appeared . For classical information, copying is a rather simple and ordinary operation, while in quantum mechanics, in general, this turns out to be impossible.
In addition, another direction of research has made a significant contribution to this direction, which appeared in the 70s. interest in gaining complete control over single quantum systems . Prior to this, control was usually carried out on bulk samples containing a huge number of quantum mechanical systems, moreover, none was directly available. Elementary particle accelerators came to the aid of scientists, who helped to get limited access to this most notorious control of individual systems, but it is still was incomplete.
In order to control single quantum-mechanical systems, a large number of methods were subsequently developed that allow one to learn many new aspects of the behavior of such systems.
So why all these delights and tricks in the direction of achieving control over such systems? If we discard various technological reasons and leave only scientific ones, the answer will be ridiculously simple - the researchers proceeded from intuitive considerations. In science, often many significant discoveries are made when a sufficient mass of results accumulates in a new field of research. So now we are only taking the first steps in mastering this, but have already managed to get some interesting and unexpected results. So what can we expect when we still learn to fully control individual quantum-mechanical systems and transfer these algorithms and understanding to the control of the ensembles of such systems?
Just the direction of quantum computing and quantum information theory pushes us to search for new ways to manage these systems and search for opportunities to apply the knowledge gained.
And, unfortunately, despite all the efforts and popularity of this area, the results that we have today are rather scant. Modern technology is represented only by small quantum computers with a limited number of quantum bits ( qubits ), as well as some optical quantum circuits. There are even implementations of quantum cryptographic systems capable of making data transmission over long distances with absolute secrecy, but at the moment these are only prototypes of the necessary systems. Nevertheless, even they can now they can be quite useful in some practical specialized applications.
Conclusion
Let's go back to the original questions. What awaits us in the future? What is so special about quantum computing and quantum information that science, technology, and all of humanity can offer? What are the main problems that need to be addressed? Quantum computing and quantum information taught us to think about computing physically, so we found a huge amount of new opportunities in the field of communication and information processing. Of course, these areas pose a lot of tasks for physicists and engineers, and it is not entirely clear what this will lead to in the long term. Quantum computing and quantum information provide new opportunities that allow you to move from simpler to more complex. In addition, the ideas of these areas allow us to form new views on physics, which is equally important.
In the proposed article, some key goals, motivations that underlie these areas of interest were briefly and briefly reviewed. In addition, I tried to give a very short historical excursion on the part of physics, showing a part of the prehistory that led to the appearance of quantum computing and quantum information theory. In addition to physics, it would not hurt to consider, as I have already said, the history of computer science, information theory and cryptography. All this I leave for the following articles, if it arouses someone’s interest. And today, perhaps, everything.
Thanks for attention!
Source: https://habr.com/ru/post/366645/
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