IBM has almost doubled the number of processing units (qubits) in its new quantum computer, which should provide an answer to Google’s achievements in the field. The goal: to create a computer with unique computing capabilities

IBM last week announced an impressive technological-quantum achievement: it has developed a quantum computer with 127 qubits – processing units. In doing so, it almost doubled the amount of processing units compared to its previous computer, which had 65 qubits. This is another step towards the development of a useful quantum computer. In the coming year, IBM plans to reach 433 cubic meters, and in 2023 their goal is to create a working computer with 1,121 cubic meters.

A qubit, i.e. a quantum bit, is the most basic processing unit of a quantum computer, just as a comet is the most basic processing unit of a classical computer, i.e. a standard computer. Classic computers are based on bits: hardware units that can be in one of two modes – off or on, marked with 0 and 1. These zeros and ones together make up the binary code in which all the data and commands necessary for the functioning of each computer are written, from the simplest to the supercomputers.

Qubit is the equivalent of a bit in the world of quantum mechanics. Like the bit, the qubit can be in one of two states, 0 or 1. But since it is a quantum system, there is one fundamental difference: unlike a regular bit, a quantum bit can be in a state called superposition, which is a kind of intermediate state that is not 0 and not 1, but a kind A combination of a bit of each. Only when an examination is made of his condition will he “collapse” into one of the two situations, that is, he will move to one of them. The probability for each of the two states after the collapse is equal to the relative share that each had in the intermediate state. This feature allows the quantum computer to do things that classical computers are unable to do, but also poses other obstacles and challenges.

Scientific and engineering challenge

In classical computers, the bits are almost always represented by electrical circuits through which current (1) passes or no current (0) passes. In contrast, the systems designed to implement qubits are still in development, and it is not clear what method will be chosen in the end. IBM develops qubits based on electrical circuits with superconducting components. Google also uses technology similar to the development of its quantum computer, which currently has 72 qubits. Here it is worth noting that the number of qubits is not the only measure for comparing quantum computers, so it is difficult to determine which company is more advanced in the development of its quantum computer.

Quantum computers are designed to be able to perform certain tasks efficiently and significantly improve the calculation times in them compared to a regular computer. This means that there are problems that a classic computer needs a long time at an unreasonable level to solve – between a few months and many years, while a quantum computer will be able to complete them in a reasonable time. Such tasks can be for example simulating quantum systems like advanced materials or chemical molecules important to the pharmaceutical industry, performing mathematical operations used by search engines like Google, optimizing complex systems or encryption and breaking codes.

The development of the quantum computer poses a complex scientific and engineering challenge to developers. The qubits in the quantum computer are required to communicate with each other, or rather to perform a process called quantum entanglement between them, so that we can truly harness the power of the computer. In the interlacing process, an interaction is created between two distant qubits, so that the quantum state of one of them affects the quantum state of the other. The more complex the interaction between the qubits, the more prone it is to interruptions and errors, known as “noise”. Such noise may too early measure the quantum state of the qubit and thus destroy the superposition in which it is located, i.e. cause it to lose its quantum properties. To this end, quantum computer developers are working to improve the architecture in which the qubits will be placed and the ways to intertwine them.

Quantum superiority

In recent years, several research companies and laboratories have been working to achieve “quantum superiority”, that is, to succeed in performing a task on a quantum computer that will be too difficult and time-consuming for a classical computer. This is a far-reaching goal for a tiny quantum computer consisting of only a few dozen qubits. For comparison, the working memory of an average commercial laptop is about 16 gigabytes, which is 128 billion bits. Even in tasks tailored specifically to the features of the quantum computer, the huge size gaps between current quantum computers and the powerful classic computers available to us today still tip the scales in favor of the classic computer.

In 2019, Google announced that it had achieved quantum superiority, using the quantum computer it was developing to generate a statistical distribution function that posed a difficult computational challenge to a classical computer. However, a year later, scientists from China published an article in which they showed that the same distribution function can be generated using Alibaba’s classic supercomputers. So the race to achieve quantum superiority continues.

IBM’s declaration is not about achieving quantum superiority. In fact she did not announce any important task that her new quantum computer had performed. Its achievement is the very development of the new computer, which in the future IBM intends to use in order to achieve the desired quantum superiority. Which lines will the new computer bring with it regarding the power of quantum computers? We’ll have to wait and see.