Quantum computing technology and industry are advancing hand in hand. Research directions such as superconductors, photons, ion traps, and neutral atoms are “blossoming”, and it is still unknown who will win.

In the story setting of the sci-fi movie “The Wandering Earth”, quantum computers play an extremely important role, especially the 550 series: 550C is a “self-aware, self-adaptive, self-organizing, reshapeable compiling and computing core, connected to hardware The underlying operating system can later be generated in real-time.” This means that it has plug-and-play and complete control over any hardware; 550W has stronger computing power and can simultaneously control the construction and operation of tens of thousands of engines around the world. It also has self-awareness and named itself MOSS. Taking on the two missions of destroying mankind and saving mankind, he becomes the biggest BOSS in the movie.

Does such a “supernatural power” quantum computer exist in real life?

”Undecided, quantum mechanics.” This widely circulated stalk expresses the unfathomableness of quantum mechanics in the hearts of the masses. Although it is true that this discipline cannot be explained clearly in a few words, since its creation in the early 20th century, it has actually changed the way humans view the world.

The history of quantum computing dates back to the 1980s. In 1982, American theoretical physicist and Nobel laureate Richard Feynman proposed the idea of quantum computing in a paper, arguing that quantum computing can solve complex problems faster than traditional computers. In 1994, Peter Hull, a scientist at Bell Laboratories in the United States, disclosed how his quantum algorithm can quickly decompose the prime factors of large numbers—to decompose a 1,000-digit number, it takes about 10 Jing for a traditional computer (1 Jing = 10,000 trillion ) years, but with quantum computers, it only takes about 20 minutes.

Why are quantum computers so powerful? Traditional computers use classical binary code, each bit has only one state, either 0 or 1, and the basic information unit of quantum computer is qubit, which can express 0 or 1 at the same time, which is the unique phenomenon of quantum superposition . There are 2n possible states for N qubits, which increase exponentially as N increases. Scientists estimate that when N ≥ 50, quantum computers will exceed the computing power limit of existing computers.

On the other hand, the quantum superposition state also enables qubits to have ultra-high storage capacity. In existing memories, a storage unit stores only one bit, and the capacity is the sum of the number of storage units. Due to the quantum superposition feature of quantum memory, a storage unit can store N states of 1 qubit at one time. Assuming a 100-qubit register, its theoretical capacity is equivalent to 1.26×1021 TB, far greater than the sum of all electronic storage capacities on Earth.

Quantum entanglement is another wonderful phenomenon of quantum mechanics. Entangled qubits are always correlated, even if they are infinitely far apart, and by measuring the state of one qubit, we can know the state of the other without directly measuring it. Quantum entanglement can also be used to enable quantum teleportation, which is used to transfer information between different parts of a quantum computer in real time.

Quantum computers give human beings so much room for imagination in the future. In recent years, the “quantum supremacy competition” among countries has been in full swing. Since 2011, Canada and the United States have launched the first generation of self-developed quantum computers. China is the third country in the world that has the ability to deliver quantum computers. In February 2023, China’s first quantum computing company, Benyuan Quantum Laboratory, was open for tours, limited to 30 people, and no filming was allowed during the whole process. People still don’t know what these lucky people saw.

In this vast and bright future, in fact, the hardware equipment of quantum computers is still in the early stages of development.

Stability is the biggest challenge currently facing quantum computers. Quantum states such as superposition and entanglement are very delicate and easily changed by the external environment, which means that quantum computers must operate under extremely controlled conditions, such as extremely low temperature and extremely limited space, to protect them. Free from any environmental “noise”. The fragility of quantum states means that quantum computers cannot yet accurately generate large computational chains.

Another issue is versatility. Computers are divided into special-purpose computers and general-purpose computers. At present, the so-called quantum computing is almost all based on special-purpose computing for specific tasks. Quantum computing has indeed shown advantages in certain tasks, but it is still not as good as ordinary computers in most tasks. The quantum computing prototypes that have been made so far are not yet of practical value.

Today, the significance of quantum computer research is still limited to verifying the feasibility of quantum computing—you must know that it takes a long time and countless unimaginable challenges to go from feasibility verification to test machines, mass production machines, and then to commercialization. At present, quantum computing technology and industry are advancing hand in hand, and research directions such as superconductors, photons, ion traps, and neutral atoms are “blossoming”, and it is still unknown who will win.