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It used to be a qubit that went west after about 1,000 ticks, and can now persist to 10,000 ticks. Continuing for 0.0005 seconds is not easy!
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TikTok Video:
https://www.douyin.com/video/7030624585003355422
Released on November 15, 2021, this video has been viewed more than 910,000 times and has reached 27,000 likes
Highlights:
Recently, the Beijing Institute of Quantum Information Science released a new achievement: a long-life superconducting qubit chip. What is "long life"? Many members of the public came forward with interest to inquire, thinking that they could prolong their lives through quantum technology. Unfortunately, they were disappointed, and the object of this work was not people, but qubits. The so-called long life is only 503 microseconds, that is, 0.000503 seconds.
You may wonder: Shouldn't this be called short lifespan? It's actually called long life?! Dr. Jin Yirong, a disciple of HKUST and a researcher at the Beijing Institute of Quantum Information Science, wrote an article (Superconducting qubit life exceeds 500 microseconds – a moment in the world, but of great significance| Back to Simplicity), explains the principle here.
Just as the basic unit in the computer we see every day is called bits, the basic unit of a quantum computer is called qubits. Bits have only two states, 0 and 1, but qubits have an infinite number of states, and it can be in any "superposition state" of the two basic states of 0 and 1. Using this property, quantum computers can achieve many magical functions, which are expected to greatly surpass traditional computers.
However, due to environmental interference, the state of the qubit may change, and in layman's terms, this quantum state is dead. Therefore, we call the time that a qubit keeps information from being lost as its "lifetime". This lifetime is actually a statistically characteristic time, and the professional name of physics is "decoherence time" (decoherence time). Previously, the lifespan of qubits realized with superconducting systems was about 10-100 microseconds, which was much shorter than a blink of an eye. Now it's up to 500 microseconds, which is of course a long lifespan!
You may want to ask, what is so short enough? The answer is that quantum computers also have an important characteristic time, which is the time required for a single operation. For superconducting qubits, the time to do a quantum gate operation is about 10-100 nanoseconds, and we can compare this time to a "tick". That is to say, a qubit that used to drive the crane west after about 1,000 ticks can now persist to 10,000 ticks. This allows you to do a lot more, so it's an important step forward. Now you understand what long life means, right? Continuing for 0.0005 seconds is not easy!
Jin Yirong told everyone that this is achieved through innovation in materials and micro-nano processing technology. However, there are still many dangers and obstacles in front of the quantum computer, such as quantum error correction, so this is far from the end of the Long March, and even the stop point is not counted. How to generalize these technologies to chips that contain more qubits, and how to further improve the fidelity of quantum gate manipulation on this basis, will be the next more important challenges.