The race is in full swing. The world’s leading companies are trying to create the first quantum computer, which is based on technology, long promising scientists to assist in the development of marvelous new materials, the ideal data encryption and accurate forecasting changes in the Earth’s climate. Such car will appear not earlier than ten years, but that’s not stopping IBM, Microsoft, Google, Intel and others. They literally lay out the piece of quantum bits – or qubits – on the processor chip. But the path to quantum computing includes much more than the manipulation of subatomic particles.
A qubit can represent 0 and 1 simultaneously, due to the unique quantum phenomenon of superposition. This allows qubits to hold a huge number of calculations at once, significantly increasing computational speed and capacity. But there are different types of qubits, not all of them are created equal. In programmable silicon quantum chip, for example, a bit value (1 or 0) is determined by the direction of rotation of the electron. However, the qubits are extremely fragile, and some need a temperature of 20 millikelvin – 250 times colder than deep space in order to remain stable.
Of course, a quantum computer is the processor. These new generation systems will require new algorithms, new software, links and a bunch of not yet invented technologies, benefiting from the enormous computational power. In addition, the results of calculations will need to be stored somewhere.
“If it hadn’t been so hard, we would have made one,” says Jim Clark, Director of quantum hardware in Intel Labs. At CES this year, Intel introduced the 49-kubicova processor codenamed Tangle Lake. A few years ago, the company created a virtual environment for tests of quantum; it uses powerful supercomputer Stampede (Texas University) to simulate the 42-cubatobaco processor. However, to really understand how to write software for quantum computers, we need to simulate hundreds or even thousands of qubits, says Clark.
Scientific American took Clark’s interview in which he talked about the different approaches to creating the quantum computer, why they are so fragile and why this whole thing takes so much time. You will be interested.
Than quantum computing differ from the traditional?
A common metaphor that is used to compare two types of calculations is a coin. In a traditional computer processor is the transistor either “heads” or “tails”. But if you ask which side the coin looks when spinning, you will say that the answer might be both. So arranged quantum computation. Instead of the usual bits that represent 0 or 1, you have a quantum bit that is both 0 and 1 as long as the qubit will not stop spinning and come to rest.
The state space or the ability to sort through a huge number of possible combinations – in the case of a quantum computer exponentially. Imagine that I have in my hand two coins and I toss them in the air at the same time. As they spin, they represent four possible States. If I toss three coins into the air, they will represent eight possible States. If I get thrown in the air fifty coins and will ask you how many States they represent, the answer is a number that can’t calculate even the most powerful supercomputer in the world. Three hundred coins are still a relatively small number would carry more States than atoms in the Universe.
Why qubits are so fragile?
The reality is that coins or qubits, eventually stops spinning and quanta collapse into the dark in a certain state, whether it is heads or tails. The goal of quantum computing is to maintain their rotation in a superposition of the set of States for a long time. Imagine that on my Desk spinning a coin and someone is pushing the table. The coin could fall faster. Noise, temperature changes, electric fluctuations or vibration can all interfere with the qubit and lead to the loss of their data. One of the ways to stabilize the qubits of certain types is to keep them cold. Our qubits are working in fridge the size of a barrel is 55 gallons and use a special isotope of helium for cooling to a temperature of almost absolute zero.
As different types of qubits differ?
There are at least six or seven different types of qubits, and about three or four of them actively considered for quantum computer. The difference is in how to manipulate the qubits and make them interact with each other. Need to two qubit communicated with each other to carry out large “complicated” calculations, and different types of qubits are entangled in different ways. I described a type that requires emergency cooling, is called a superconducting system that includes a processor Tangle Lake, and quantum computers built by Google, IBM and others. Other approaches use oscillating charges caught ions held in place in a vacuum chamber with laser beams which play the role of qubits. Intel develops systems with trapped ions, because it needs deep knowledge of lasers and optics, we can not do it.
However, we study a third type, which is called the silicon spin qubits. They look just like traditional silicon transistors, but operate on a single electron. Spin qubits using microwave pulses to control the spin of the electron and release its quantum of force. Today this technology is less Mature than the technology of superconducting qubits, however, may be much more likely to scale and become commercially successful.
How to get to this point here?
The first step is to make these quantum chips. At the same time, we conducted a simulation on a supercomputer. To run a quantum simulator for the Intel, we have about five trillion transistors for modeling 42 qubits. To achieve the commercial reach to about a million qubits or more, but starting with a simulator like this, you can build the basic architecture, compilers and algorithms. Until we find some physical system that will include from several hundred to thousands of qubits, it is unclear what kind of software we will be able to run. There are two ways to increase the size of such a system: one is to add more qubits, which will require more physical space. The problem is that if our goal is to create computers in a million qubits, mathematics will not allow them to properly scale. Another way is to shrink the inside dimension of the integrated circuit, but such an approach would require a superconducting system, and it needs to be huge. Spin qubits in a million times less, so we are looking for other solutions.
In addition, we want to improve the quality qubits that will help us to test algorithms and create our system. Quality refers to the precision with which information is transmitted with time. Although many parts of the system will improve the quality, the greatest gains will be achieved through the development of new materials and the improvement of the accuracy of microwave pulses and other control electronics.
Recently, the Subcommittee on digital trade and consumer protection United States held hearings about the quantum computing. What legislators want to know about this technology?
There are several hearings of various committees. If you take the quantum calculations, we can say that it is computing the next 100 years. For the United States and other governments quite naturally be interested in their opportunity. The European Union has a plan for billions of dollars in funding for quantum research across Europe. Last fall, China announced a research base to $ 10 billion, which will focus on quantum information science. The question is than: what can we do as a country at the national level? National strategy for quantum computations should be run by universities, governments and industry working together on different aspects of technology. Standards are certainly necessary from the point of view of the communications or software architecture. The labor force is also a problem. Now, if I open the vacancy of expert on quantum computing, two-thirds of the applicants are likely to be from outside the US.
What is the impact of quantum computing on the development of artificial intelligence?
As a rule, the first proposed quantum algorithms will be dedicated to security (e.g., cryptographic) or chemistry and modeling of materials. This problems that are fundamentally intractable for traditional computers. Nevertheless, there are lots of startups and groups of scientists working on machine learning and AI with the introduction of quantum computers, even theoretical. Given the time frame required to develop the AI, I’d be expecting traditional chips, optimized specifically for algorithms AI, which, in turn, will influence the development of a quantum chip. In any case, the AI will definitely get a boost from quantum computing.
When we see that working quantum computers will solve a real problem?
The first transistor was created in 1947. The first integrated circuit in 1958. The first microprocessor Intel which contained approximately 2,500 transistors – come to light only in 1971. Each of these milestones was divided more than a decade. People think that quantum computers already around the corner, but history shows that any achievements require time. If in 10 years we will have quantum computer on a few thousand qubits, it’s definitely going to change the world just like it changed the first microprocessor.
How close are we to creating a quantum computer?
Ilya Hel