February 10, 2023
Quantum Computer
On January 26, 2023, the SRF program “Einstein” talked about quantum computers. The electronic devices work with bits, which are subject to the binary system. The bits have 2 different states: 0 or 1. Where does that come from? The electron has an intrinsic angular momentum with 2 different orientations. The so-called electron spin of an electron thus has 2 states: either +1/2 or -1/2. Thus bit is (1) or (0).
What is a Qbit?
The Einstein broadcast of January 26, 2023 only speaks of atoms or dust particles. Which atoms are supposed to be involved is not mentioned. This is also not important for the time being. When atoms are meant (there are probably also chemical compounds among the dust particles) one also speaks of particles. The particles, which are usually in a state of suspension, have 3 different degrees of freedom: translation, rotation and, at higher temperatures, vibration. At room temperature, the particles are in a state of vibration. The sample must therefore be cooled down to absolute zero, -273°C, so that the particle only rotates.
Some quantum physics
The arbitrary atom (but then there should be several) only revolves around itself. The matter is probably a bit more complex. Now some quantum theory comes into play to explain it. The atom is enveloped by an electron configuration. The electrons are distributed around the atom in several shells depending on their state or distance. There is the s, p, and d shell. The s shell can hold a maximum of 2, the p shell 6, and the d shell a maximum of 10 electrons. Now the Pauli principle comes into play. The electrons have to pair up, but this only works if both electrons have opposite spins. An electron pair consists of an electron with spin = +1/2 and an electron with spin = -1/2. But never with the same spin! The s-shell consists of a maximum of 1 electron pair, the p-shell of 3 and the d-shell of 5 electron pairs.
Spin orbit coupling, a possible derivation of Qbit
At the very periphery of an atom there is an unpaired electron in the p or d shell. An unpaired electron in the s shell must rise to a higher empty p or d shell when excited. The unpaired electron in the p or d shell now also circles around the atomic nucleus. Since the electron already has its own angular momentum, this results in a total angular momentum.
Figure: Purple ring, atomic nucleus. Light blue circle, orbit of the electron around the nucleus. Arrow up is the resulting total angular momentum.
Since the electron can have two different states, this results in two different total angular momenta. From this you can see why the atom called a qbit can be both 1 and 0. An unpaired s-electron does not revolve around the atomic nucleus. That’s what the textbooks say. However, in the ground state, the sodium atom has an unpaired s electron in the outermost 3s shell. When excited, e.g. with a laser, the 3s electron rises to the 3p state and can orbit the atomic nucleus and 2 energy levels are created at 589.76 nm and 589.16 nm. A fine structure of the spectrum is created. This has been observed with the sodium vapor lamps used for street lighting. However, this explanation does not prove whether the spin-orbit coupling is related to the qbits.
Calculating the possibilities of a quantum computer
Let’s get back to the article in the show “Einstein” from January 26, 2023. The moderator and the scientists at the IBM Institute in Rüschlikon do not mention exactly what a Qbit is.
A single Qbit can be both 1 and 0. This means that the following combinations are possible for a single Qbit. 0 and 1, so 2 combinations.
With 2 Qbits result 00, 01, 10 and 11 are 4 combinations.
At 3 Qbits 000, 001, 010, 011, 100, 101, 110, 111 you get 8 combinations
With 4 Qbits, the IBM Institute already counts 16 combinations or possibilities
With 10 Qbits it is 1024 20 qbits = 1048576
Now how do you get these results?
With the Qbit we are dealing with only 2 states, namely 0 and 1.
We now raise these 2 states to the power of the number of available Qbits. =2 high x = 2×
With 20 Qbits you calculate 2 to the power of 20 which gives 1048576. You calculate 2 ²º = 2 high 20
100 Qbits already result in a number with 31 digits: 1 267 650 600 228 229 401 496 703 205 376 = 2¹ºº
1000 Qbits now result in a number with 302 digits.
In fact, several tens of millions of atoms or particles can accumulate in a lump of dust with a diameter of e.g. 6 mm. Let’s get back to the sodium atom. 1 mol, that is Avogadro’s number, consists of 6*10²³ atoms. There is space for one mole of sodium atoms in a cube-shaped container with an edge length of about 3 cm. It is hardly possible that a quantum computer will still work with it. The vessel in which the Qbits sample is supposed to be located must be completely evacuated for the time being. Otherwise, air particles such as O2, N2, CO2 and other chemical particles will get in the way of the Qbits or even react. In addition, as explained in the program, the container must be cooled down to the Kelvin temperature (=-273°C). Cooled down and evacuated, the qbits are now vibration-free and there are hardly any interactions, the atom only rotates or the electron spins around the atomic nucleus, if the spin orbit coupling is actually meant. The qbits are then probably also loosely distributed in the vacuum of the vessels on the floor or maybe even floating motionless.
Quantum computers have huge potential
Not only the speed, but also the artificial intelligence, which already gives a lot today, will be massively increased. Finding the shortest or most optimal route in a big city almost instantly, as shown in the show, Einstein, is just a simple example. With the quantum computer, drugs can be created for each individual human and animal body. And much more: Material transport at the speed of light in space could become a reality. The planet Mars could be made habitable with remote-controlled robots. Closed systems, snow groomers, proton-protected buildings with oxygen plants, chemical factories, a kind of proton-protected shell around Mars and much more are conceivable. A biological system, initially in closed systems, could be set up on Mars.
What are the disadvantages and dangers?
The container in which the Qbits are located must be cooled down to 13 times the freezing temperature. That costs a lot of energy. The dangers are much greater. An 8-digit password with upper and lower case letters, prime numbers, characters like ç,/&[}) etc is very difficult to hack. It takes several years. With a quantum computer, a few days or even a few hours are enough, depending on the number of qbits. The passwords will probably be at least 1000 characters long and also contain letters in Russian, Arabic, Hebrew and/or other language groups. The passwords intended to protect against quantum computer attacks will likely have to be purchased. If a criminal organization or company, or even one or a few people own a quantum computer or simply have access to it for the first time, the potential danger is huge, exceeding all dimensions. The whole world can be checked mate, the whole civilization could be annihilated. Transportation systems, hospitals, electric power plants, the Pentagon, etc. can all be shut down in a short time. Imagine that.