O computerquantum is a programmable device capable of performing calculationsand algorithms through the manipulation and reading of information stored in quantum systems, such as atoms, molecules, protons, electrons and photons. In this type of computer, bitsquantum, which, by its very nature, make this type of computer capable of performing tasks that would take thousands or even millions of years to be made by electronic computers.
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How does the quantum computer work?
You computersquantum are completely different from ordinary computers, which are based on passing electric current through small devices semiconductors, called transistors. This new type of computer can work from the most diverse quantum systems, however, the most popular implementations read the spin, a quantum property present in particles such as protons, photons and electrons.
The logic behind the quantum computer is also a little different from what is used in computers classics, which operate through logical sentences whose possible results are only the numbers 0 and 1.
The difference between electronic and quantum computers is that due to natureprobabilistic gives quantum physics, before we read the bitquantum, its status can be not only 0 or 1, but also the intersection between these states. It is as if in quantum computers, answers like yes, no and both were admitted simultaneously. If you want to better understand the probabilities of the quantum world, visit our text on the Heisenberg's Uncertainty Principle.
![53-qubit quantum processor, developed by Google in 2019. [1]](/f/b2e772f0a0a83a15588e82ba83f1d8e9.jpg)
The strange property that makes quantum computers so special is called collapsegivesoccupationinwave. All quantum systems are completely described by a respective wavefunction, but before we look at a quantum system, looking for some of its physical greatness that can be measured (mass, electric charge, magnetic field, for example), the wave function can support more than one value for each of these quantities and there are probabilities that each of these values will be measured.
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You might be asking yourself – what is the advantage of not knowing in advance the possible values of a quantum measure? The answer is: before doing any calculations, for example, the nature of quantum bits ensured that the correct answer was among the possibilities. In other words, we can say that the computer had already considered many results, even before getting the answer of the calculation. This makes the timecomputational that is spent on solving complex problems, either drastically reduced.
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Quantum Computer Possibilities
But after all, what could we do with a quantum computer? Very likely, the quantum computers will not be used for trivial purposes like browsing the internet or watching a video, since, for these purposes, electronic computers are quite efficient, in addition to being much cheaper than quantum computers.
However, when we talk about calculationscomplexes, like those involving the cryptographyinpasswordsbanks, the use of quantum computers will be of great help. If we are able to make quantum computers fully functional devices, we will be able to simulate things we never thought possible, like Earth's climate dynamics, galaxy formation, simulations of living systems, and many other possibilities.
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Qubits - the quantum bits
Quantum bits are often called qubits (quantum bits). These qubits represent a huge leap from the bits used by electronic computers: they can have states 0 and 1 simultaneously. In practice, it's as if the quantum computer's capacity is exponential in relation to the number of bits: a 1-bit quantum computer is equivalent to a classic 2-bit electronic computer and a 2-bit quantum computer is equivalent to a 4-bit computer electronics. See below a table that relates the capacity of quantum bits to their correspondence with classical bits:
Quantity of quantum bits |
Classic bit matching |
1 qubit |
2 bits |
2 qubits |
4 bits |
10 qubits |
1024 bits |
20 qubits |
1048576 bits |
64 qubits |
1,84.1019 bits |
512 qubits |
1,34.10154 bits |
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2019 Quantum Processor
Recently, Google researchers claimed to have reached the "quantum supremacy", because they were able to perform, in 200 seconds, a calculation that the most advanced computer in the world, the Summit, from IBM, would take about 10,000 years. The experiment carried out by the researchers used 53 qubits, corresponding to about 1016 classic bits, to keep the quantum processor fully functioning, the computer was kept at very low temperatures, around 20 mK (0.02 K).
The results obtained by the experiment suggest that the concept behind the machineinTuring, that theoretically is universal and capable of simulating any computational model, could be wrong. This is because classical computers, based on Turing's theoretical set, are not able to perform the tasks done by the quantum processor, at least not with the same speed nor with the same precision.
Image credit
[1] nature
By Rafael Hellerbrock
Physics teacher
