The reporter saw with the help of a microscope at Zhejiang University that the size of the superconducting qubit chip is about 1 square centimeter, and 20 qubits are evenly distributed around the central resonator, just like each branch connected by the central hub.
It is understood that this is the fourth generation circuit design scheme iterated by the laboratory of superconducting quantum computing and quantum simulation team of Zhejiang University. The goal is to enable direct 'communication' between any two qubits to achieve global entanglement. Global entanglement is to let all quantum bits work together. Quantum manipulation is the technical commanding point of quantum computing, and the realization of global entanglement is the symbol to test whether the manipulation is successful.
Researchers said that computers use '0' and '1' for information storage and processing. In classical computers, a bit is like an ordinary switch, or 0 or 1. Due to the characteristics of quantum entanglement and superposition, a quantum bit can represent 0 and 1 at the same time. " Imagine a coin standing still on the table, you can only see its front or back; When you rotate it quickly, you see both the front and the back. Thus, a quantum computer is like many coins dancing at the same time. " The researchers said.
Under the control of the laboratory, the researchers captured the coherent states of 20 artificial atoms when they 'started' in just 187 nanoseconds (one millionth of the time required for people to blink). After many transformations, they finally formed an entangled state with two opposite states at the same time. Manipulating these qubits to generate global entangled states indicates that the team can really mobilize these qubits.
The number of quantum bits is one of the important indexes to measure the performance of quantum computer. Some studies believe that once the number of quantum bits reaches more than 50, it can show the computing power beyond the supercomputer when dealing with some specific problems. " A remarkable feature of our chip is that all bits can be connected to each other, which can improve the operation efficiency of quantum chip and is one of the important reasons why we can take the lead in realizing 20 bit entanglement. " The researchers said.