Scientists from the University of Science and Technology of China (USTC) led by Pan and Lu Chaoyang have developed a new way to simulate a quantum physics phenomenon known as the fractional quantum anomalous Hall state using photons instead of electrons which has been the traditional way. 

Observation of fractional quantum anomalous Hall states using photons: A breakthrough research by Chinese scientists at USTC

Scientists from the University of Science and Technology of China (USTC) led by Pan and Lu Chaoyang have developed a new way to simulate a quantum physics phenomenon known as the fractional quantum anomalous Hall state using photons instead of electrons which has been the traditional way to achieve this state. 

The Hall effect refers to when a current-carrying conductor or semiconductor is passed through a solid material placed in a magnetic field perpendicular to the direction of the current and the magnetic field generates a measurable voltage. It was discovered by the American scientist Edwin Hall in 1879 and has since been applied in electromagnetic sensing. This led to the observation of an integer quantum anomalous Hall (QAH) effect in 2023 as the existence of the quantum Hall effect at zero magnetic fields.

This represents a pivotal shift in quantum physics research with profound implications for both theoretical understanding and practical applications.

Firstly, by using photons to simulate this quantum state, the USTC team circumvents some of the most challenging aspects of traditional quantum Hall state experiments. Typically, these experiments require extremely low temperatures, high-purity materials, and strong magnetic fields. By overcoming these hurdles, the new method not only simplifies experimental setups but also enhances the feasibility of studying quantum Hall states under less restrictive conditions.

Furthermore, the creation of "Plasmonium," a new superconducting qubit developed by the team, marks a significant innovation in quantum technology. This qubit's higher anharmonicity allows for better control and manipulation of quantum states, paving the way for more precise and comprehensive measurements. Such advancements are crucial for the progress of quantum computing and simulation technologies.

The traditional means of preparing and observing a quantum Hall state involves extremely low-temperature environments, pure two-dimensional materials, and strong magnetic fields. This process fails to measure the microscopic quantum states of the systems at single-point positions hence limiting its applications in quantum technology.

In this research, the team developed a new superconducting qubit named Plasmonium to overcome weak repulsions among photons thereby creating a higher anharmonicity in the system. This also enabled the observation of the fractional quantum anomalous Hall state. Lu reported that researchers can now access greater control and manipulation capabilities using this newly created quantum system as they can make comprehensive measurements of microscopic quantum states using the high-precision control feature of the system.

He added that an external magnetic field is not required using Plasmodium and it also allows for further controlled utilisation of the properties of the quantum states for further applications. The expectation is that, in the near future, quantum simulation technology will be applied to simulate quantum systems that are computationally difficult for classical computers leading to the supremacy of quantum computation.

In essence, this development not only represents a technical milestone in quantum physics but also signals a shift towards more accessible, versatile, and powerful quantum simulation technologies that could redefine the boundaries of scientific research and technological innovation.

The Vice President of the Chinese Academy of Science (CAS), Chang Jin stated at a press conference that this new technology has the potential to solve global problems and hopes that the advancement in quantum technology continues to rise through the efforts of the global scientific community and cooperation from the international community. He also remarked that by transforming the achievements of basic research in quantum technology into key technologies, social change and economic development can be stimulated by the introduction of innovative and quality products into the market.

Peter Zoller, a chair professor at the University of Innsbruck and recipient of the Wolf Prize in Physics, described this accomplishment as both scientifically and technically extraordinary. He emphasized that achieving this milestone has been a longstanding aspiration in quantum simulation across numerous laboratories globally.

Frank Wilczek, a Nobel laureate in physics, also commended the study as "a very promising idea" and "a very impressive experiment," highlighting that it signifies "a remarkable step" forward in quantum information processing.

This milestone of using photons to simulate the fractional quantum anomalous Hall state is truly remarkable since photons travel at the speed of light and penetrate sub-atomic and nucleic levels that electrons cannot. This means faster computations for complex problems performed within stable environments.