What is quantum computing and quantum superiority?

Let's talk about quantum first.

"Quantum" is not a specific particle, but the general name of material objects in the quantum world, which can be microscopic particles such as photons, electrons, atoms, nuclei and elementary particles, or a macroscopic quantum system, such as "Schrodinger's cat".

In our daily experience, the physical quantities and states of macroscopic world objects are always determined at a certain moment. For example, a light bulb is either on or off. It is impossible to turn it on and off at the same time.

But in the quantum world, "flickering light bulb" exists, because quantum has superposition state. Quantum superposition means that a quantum system can be in the superposition state of different quantum States. In short, it is the superposition of two states.

"Schrodinger's Cat" is a thought experiment to explain quantum superposition: the cat is kept in an opaque box with a device that can release toxic gases. If you don't open the box to observe (measure), the cat will be in a dead/alive superposition state.

Besides superposition states, quantum has another important feature-quantum entanglement. Quantum entanglement means that the behavior of one particle will affect the state of another particle, even if it is far away. When one of them is operated and its state changes, the other will immediately change its state.

The quantum computer works through the characteristics of quantum mechanics, and the simulation subsystem obtains the solution by using quantum equations. Due to the natural parallel processing ability of quantum system, the computer it realizes is likely to far exceed the classical computer.

The information unit of a classical computer is a bit, which is generally represented by "0" and "1". One, either "0" or "1". The information unit of quantum computer is "qubit". As mentioned above, quantum has the characteristic of superposition state, so the qubit can be in the state of "0" and "1" at the same time.

Due to this superposition characteristic, quantum computers can have powerful parallel computing capabilities. When designing quantum computers, we usually use the characteristics of quantum entanglement to entangle one particle with other particles to further improve the parallel computing ability. In short, using quantum superposition and quantum entanglement, the computing power can be doubled.

Google's research results prove the feasibility of parallel computing, but it is very difficult to manufacture quantum computers, and they must work at extremely low temperatures to ensure that qubits are not affected by the external environment. But it means a lot. It can be predicted that in the near future, with the development and popularization of 5G and 6G technologies, future computers don't need to be equipped with a CPU. Many local computers use a CPU to handle tasks, and then transmit them at high speed through the network. User terminals only need to present content. And its own computing power can be applied to almost all fields, helping human beings to extend their tentacles further.

One small step for Google, one giant step for mankind!