China finds quantum anomaly Hall effect supercomputer becomes possible

http://news.cnblogs.com/n/193989/

The quantum anomaly Hall effect, for ordinary people, is clumsy and obscure. But in the eyes of physicists, it is "magical" and "wonderful". Because its discovery could lead to the next information technology revolution. Using this technology to design integrated circuits and components, the China supercomputer is expected to be as big as a tablet computer, and smartphone memory may be raised by hundreds of thousands of thousand.

After the first observation of the quantum anomaly Hall effect from the experiment, the vice president of Tsinghua University Shikikun and his team received wide attention from outside.

"We are trying to improve the temperature of the physical phenomenon of observing the quantum anomaly Hall effect, hoping to ascend from the original 零下273摄氏度 to the 零下269摄氏度." Shikikun said in an interview with reporters. For more than half a year, they have been striving for further in-depth research and application of the quantum Anomaly Hall effect. Shikikun said: "零下269摄氏度 is the liquefied temperature of helium, is a sign of temperature." For example, the hospital's CT work is this temperature. If this goal can be achieved, it will lay a good foundation for the application. ”

This March 15, the Shikikun team's research results were published online in the US journal Science. April 12, the magazine published the paper, its "Outlook" section also published a "Complete quantum Hall family Trio," the review article. The article said Chinese scientists "confirmed the long-awaited existence of the quantum anomaly Hall effect, which is the last member of the Quantum Hall family".

In condensed matter physics, the quantum Hall effect occupies a very important position. The experimental findings of the total number of the Hall effect and fractional quantum Hall effect were awarded the Nobel Prize in Physics in 1985 and 1998 respectively.

To understand the quantum anomaly Hall effect, we must first understand the quantum Hall effect. For example, when we use a computer, we will encounter problems such as computer fever, energy loss, and slow speed. This is because the electronic movement in the normal chip does not have a specific orbit, colliding with each other and causing energy loss. The quantum Hall effect can make a rule for the motion of electrons, allowing them to "indomitable" on their respective runways. "It's like a sports car, which normally runs on a crowded farmer's market, and in the case of the quantum Hall effect, it can be on a high-speed road that is not interfering with each other." "Shikikun a figurative analogy.

But the creation of the Quantum Hall effect requires a very strong magnetic field, "equivalent to 10 large computer magnets, which are bulky and expensive, unsuitable for personal computers and laptops," Shikikun said, adding that the beauty of the quantum anomaly Hall effect is that no external magnetic field is needed, The quantum Hall state can be realized in 0 magnetic fields, and it is more easily applied to the electronic devices that people need everyday.

From the 1988 US physicist Haldane suggested that there might be a quantum Hall effect that did not require an external magnetic field, and it was more than 20 years before our scientists had a perfect ending to this prophecy. He Ke, a deputy researcher at the Physics Institute of the Chinese Academy of Sciences, told reporters: "The quantum anomaly Hall effect is very difficult to achieve and requires accurate material design, preparation and regulation." Although scientists have been proposing several different approaches over the years, the materials and structures required are very difficult to prepare, so the experiment is progressing slowly. ”

"It's like asking an athlete to have Liu Xiang's speed, Yao Ming's height and Guo Jingjing's dexterity." It is quite difficult to achieve any of the above in the actual material, but to meet these three points is a big challenge for the experimental physicists. "Wang Yahi, a professor at Tsinghua University, describes the rigor of the experiment to the material requirements," the team member said.

Shikikun team after nearly 4 years of research, growth has measured more than 1000 samples. Finally, they developed a high quality Cr doped (BI,SB) 2te3 topological insulating magnetic film using the molecular beam epitaxy method, and successfully observed the quantum anomalous Hall effect on the very cryogenic transport measuring device.

"We are encouraged by the growing emphasis on basic scientific research in the country," said Shikikun, who is concerned about the outside world. Any phenomenon from the discovery of the original reason to the application, all need different fields of scientists and industry to work together. "As to when the supercomputer can be turned into a tablet computer, Shikikun said rigorously:" This is achievable in principle, but it requires a major breakthrough in terms of temperature and material. The application potential of the quantum anomaly Hall effect is very large, but it is difficult to predict when it can be applied in future. There may also be an unexpected, more important application. We will work with more people to carry forward the research in this field and push it towards the application direction. ”