A team of researchers in China claims to have provided the first conclusive demonstration of the “ quantum advantage ” – using quantum mechanics to make calculations that would be very slow on classic computers. The research group at the Chinese University of Science and Technology collaborated with the Shanghai Institute of Micro-Systems and Information Technology (SIMIT) and the Parallel National Computer Engineering Research Center of the Chinese Academy of Sciences to build a quantum computer prototype in which as many as 76 photons were seen emerging from a network of 100 channels. Last year, Google caused a stir when it announced that it had reached “quantum supremacy,” a term that defines a quantum computer’s ability to perform a calculation that is practically impossible on a traditional supercomputer to solve, except by taking a disproportionate amount of time. In this specific case, Google’s quantum computer was run based on a Sycamore 53 qubit processor, and its algorithm was run on a 54-qubit quantity chip, each consisting of superconducting loops. The Chinese team used lasers to perform a calculation that proved mathematically impossible on ordinary computers, solving it in just a few minutes. A mission that would take the fourth most powerful supercomputer in the world over two billion years. In these cases, talking about lab tests, nothing really applies to you right now. On an experimental level, while the Google team used a superconductor cooled to near zero temperatures, the Chinese team used the photons at Sunway TaihuLight. To determine the achievement of the result, the Chinese team used a statistical test to determine the path of the photons traveling on a mirror-guided light circuit. Each photon read at the end of the process is equivalent to a qubit that reveals the result of a calculation. The team wrote code to simulate behavior and determine time accuracy compared to the most powerful computer in China. The calculation they conducted is related to the problem of sampling the boson. This problem was laid down in 2011 by two computer scientists, Scott Aronson and Alex Arkhipov. It involves calculating the probability distribution of several bosons whose quantum waves overlap each other so that the particle’s position is essentially random. The probability of detecting a boson in a given position can be calculated from an equation in several unknowns. Researchers calculated that a supercomputer would take more than 2 billion years to do what Jiuzhang did in just over 3 minutes. Figure 1: An illustration of the experimental setup for generating compressed states (Source: “Quantum Computational Feature Using Photons”). Photons like Qubit In quantum computers, bits, that is, the basic information unit of ordinary lamps, are replaced by the following – quantum bits are called “qubits” Able to deal with very complex problems thanks to greater ability to encrypt information. Issues that are quite hard to access for normal computers. The Chinese team has shown how the use of photons, the basic unit of light, can enhance quantum computing, beyond the classical isotope. They did the job at room temperature. Unlike Google, the visual system used cannot be easily reprogrammed. The advantage of an optical quantum computer is that it does not require refrigeration. Starting with laser pulses, the researchers coded information in the spatial location and polarization of specific light states. These states were performed to interfere with each other and create the photonic distribution that represents the output. The optical circuit used is the interferometer. The team used optical detectors capable of recording individual photons to measure this distribution, which in fact encodes calculations that are difficult to perform in a classic way. A quantum computer does not build its computing power on microchips and circuits but rather on quantum computing, which is based on the principles of quantum mechanics and specifically on quantum entanglement, that is, the ability of a subatomic particle to affect a different subatomic particle at a certain distance. The effect is practically instantaneous, and it is possible that the computational speed of a quantum computer is the same. Quantum computing is still in an embryonic stage, but all of these tests of excellence boost research, make it possible to simulate large systems and, above all, to guide advances in physics. Chinese researchers are in competition with other companies such as Google and IBM, which is increasingly accelerating the race towards quantum computers. .