DAMO Academy announces major progress in quantum computing, new quantum bits challenge traditional bits

Reporters learned today that at the 2022 APS Annual Meeting, a global physics event, Alibaba DAMO Academy Quantum Laboratory announced a series of latest developments, including materials, coherence time, gate control, quantum computing compilation schemes, etc. Among them, the two-bit gate control accuracy of the new quantum bit fluxonium is 99.72%, reaching the world's best level for this type of bit.

Figure: Alibaba DAMO Academy Quantum Laboratory has a two-bit (fluxonium) control accuracy of 99.72%

The American Physical Society March Meeting is one of the world's largest physics academic conferences and a grand event for reporting the latest progress in quantum computers. In addition to academic institutions, the meeting also included major international corporate teams that have invested in quantum computing, such as IBM, Google, Microsoft, and Alibaba.

The DAMO Academy Quantum Laboratory shared 8 academic reports with scientists around the world. Based on the new superconducting quantum bit fluxonium, the DAMO Academy Quantum Laboratory successfully designed and manufactured a two-bit quantum chip, achieving a single-bit control accuracy of 99.97% , and a two-bit iSWAP gate control accuracy of up to 99.72%, achieving the world's best level for this type of bit, and the performance is close to the traditional transmon bit used by the industry's major quantum R&D teams. The laboratory also implemented another native two-bit gate SQiSW on this chip, which has stronger compilation capabilities than iSWAP, with a control accuracy of 99.72%, which is the highest accuracy achieved by this quantum gate on all quantum computing platforms.

Figure: Two-bit (fluxonium) quantum chip from Alibaba DAMO Academy Quantum Laboratory

Fluxonium has the theoretical advantage of higher control accuracy than transmon, and has long attracted the attention of the academic community. However, the realization of this theoretical advantage requires overcoming many technical difficulties. There are dozens of reports on the theme of fluxonium at this conference. In addition to the DAMO Academy Quantum Laboratory, the reporting team also includes top superconducting quantum computing research groups from the University of Maryland, Princeton University, University of Chicago, UC Berkeley, MIT/Lincoln Lab, etc. The latest achievements of the DAMO Academy Quantum Laboratory have initially demonstrated the advantages of fluxonium, which relies on breakthroughs and innovations in multiple topics such as theory, design, simulation, materials, preparation and control.

The DAMO Academy Quantum Laboratory has invented a new method for manufacturing quantum devices using the epitaxial system of titanium aluminum nitride (TAN) materials , which can achieve a sharp increase in dynamic inductance under extremely low microwave losses. This material is expected to become the core component of the next generation of fluxonium chips in the Quantum Laboratory.

On another chip preparation topic, the titanium nitride-based superconducting quantum bits prepared by the DAMO Academy Quantum Laboratory can repeatedly achieve 300 microseconds in the most critical performance indicator, the coherence time, which is world-class.

A core issue in quantum chip design automation is to improve the speed of simulation calculations. In this regard, the quantum laboratory has developed a superconducting quantum chip electromagnetic simulation tool based on the surface integral equation method, which has achieved two orders of magnitude acceleration in the calculation of circuit parameters and interface losses compared to the commonly used finite element method, greatly promoting the design optimization of quantum chips.

In another effort to significantly improve large-scale quantum chip design capabilities, the DAMO Academy Quantum Laboratory integrated both chip optimization and quantum manipulation into the gradient optimization framework to efficiently jointly optimize bit design and bit manipulation schemes in a larger parameter space.

The DAMO Academy Quantum Laboratory also verified the optimization scheme for the overall computing performance of the self-developed superconducting quantum chip on fluxonium, including the general optimization compilation scheme for single-bit gates of superconducting architecture and the real-time optimal compilation scheme for another native control SQiSW gate on superconducting chips. This optimization scheme can greatly improve the overall performance indicators of quantum chips.

"Creating a scalable, high-precision qubit platform is our core strategy for realizing quantum computers. These eight reports show that fluxonium is no longer a crude toy used to demonstrate principles in academia, but has become an industrial-grade weapon that can compete with mainstream platforms," ​​said Shi Yaoyun, head of the Quantum Laboratory at Alibaba DAMO Academy. "These achievements, accumulated over three years, also reflect our path of high precision first and multi-bit later, our adventurous spirit of differentiated development, and our research style of steady and systematic advancement."

According to reports, the DAMO Academy Quantum Laboratory focuses on the realization of quantum computers and has built two hardware laboratories, Lab-1 and Lab-2 . The latter is located in the Dream Town of Future Science and Technology City in Yuhang District, Hangzhou, and provides the quantum laboratory with experimental facilities for exploring high precision on multiple bits. Previously, the DAMO Academy Quantum Laboratory has open-sourced its self-developed quantum computing simulator "Taizhang 2.0" and a series of application cases. The relevant results have been published in Nature's subsidiary journal "Nature Computational Science", and its core algorithm is widely used by academia and industry.