Domestic semiconductor quantum computing is making new progress!
Academician Guo Guangcan's team of the University of Science and Technology of China cooperated with researchers from the United States and Australia and Origin Quantum to achieve ultra-fast manipulation of silicon-based spin qubits, with a spin flip rate of more than 540MHz - the highest value reported in the world. The research paper was published On January 11 in the journal Nature Communications.
Semiconductor quantum computing is currently a popular mainstream research and application direction in the world. Companies such as Intel and TSMC, as well as Europe and Australia, are deploying this key technology route. The "high fidelity of manipulation" mentioned in this research study is challenging for researchers around the world. "High control fidelity" requires qubits to have faster control rates while having a longer quantum decoherence time.
Experimental setup and EDSR spectroscopy
The Chinese team conducted experiments in the Oxford Triton dilution chiller with a basic temperature of 10 mK (0.01 degrees above absolute zero), and by optimizing the performance of the device, the Bubblei spin blocking reading of the spin qubits of the spin qubits was completed in the double quantum dots with highly adjustable coupling intensity, and the electropolar spin resonance spectrum of the pluripotent level was observed. By adjusting different spin flip modes, ultra-fast manipulation of spin qubits at a rate of more than 540 MHz was achieved at a magnetic field of 100 mT (milli Tesla), setting a record for ultrafast spin qubit control in semiconductor systems.
According to the abstract, computing speed and coherence time are the two core indicators of qubit capability. Strong spin orbital interactions (SOIs) and relatively weak ultrafine interactions make holes in germanium (Ge) an important candidate for fast, fully electrically coherent controlled spin qubits.
At a microwave power of 9 dBm, the spin bits can be operated at a rate of 542MHz
The results show that germanium-silicon hole spin qubit system is one of the important candidates for achieving all-electronically controlled semiconductor quantum computing, which can meet the requirements of the DiVincenzo standard for scalable quantum information processors. This achievement has opened up new fields for the research of semiconductor quantum computing.
According to the paper, Wang Ke, a postdoctoral fellow at the Key Laboratory of Quantum Information of the Chinese Academy of Sciences, and Xu Gang, a doctoral student, are the co-first authors of the paper. Professor Guo Guoping, Chief Scientist of Origin Quantum and Key Laboratory of Quantum Information of chinese Academy of Sciences, Researcher Li Haiou and Researcher Zhang Jianjun of institute of Physics, Chinese Academy of Sciences, are the co-corresponding authors of the paper.
As early as more than a decade ago, Academician Guo Guangcan and Professor Guo Guoping's team began to study silicon-based semiconductor quantum computing and harvested a series of research results. In September 2017, the two professors co-founded Origin Quantum, and the team originated from the Key Laboratory of Quantum Information of the Chinese Academy of Sciences.
In 2021, the team has made a number of progress: the use of microwave superconducting resonators to achieve excitation energy spectrum measurement of semiconductor double quantum dots; the use of microwave resonant chambers to detect new interference phenomena of semiconductor quantum dots modulated by microwave drive; the application of machine learning to quantum computing, effectively improving the read fidelity of quantum chips, and greatly inhibiting the reading crosstalk effect.