Progress in one-dimensional quantum system regulation research, such as precision measurement institute

[ Instrument Network Instrument Research and Development ] Recently, the researcher of the Institute of Precision Measurement Science and Technology Innovation of the Chinese Academy of Sciences, Guan Xiwen, Quantum Accumulate Group, collaborated with Professor Adolfo del Campo of the University of Massachusetts and Professor Gentaro Watanabe of Zhejiang University to study the quantum of one-dimensional cold atomic system. New progress has been made in regulation research, and on October 17th, an interaction-driven many-particle quantum heat engine and an online publication entitled "NPJ: Quantum Information" was published online. A research paper on its universal behavior.

In this work, the quantum integrable research group and its collaborators first proposed the idea of ​​interaction control quantum heat engine, using the exact solvable model and the La Tingge quantum liquid theory system to calculate the work and heat engine efficiency of the interaction control quantum heat engine. It is found that the quantum heat engine has the largest single-particle average power near the quantum critical point, and the experimental implementation is discussed. This work reveals the universal characteristics of quantum dynamic systems from the theoretical research level, and provides a meaningful reference for quantum control and quantum gas experimental research.

Quantum heat engine is one of the hot research issues in the field of multi-body quantum physics in recent years. From the perspective of theoretical research, the traditional quantum statistical physics is not complete in describing the quantum dynamic behavior of extremely low temperature and very small scale. As the cornerstone of the various states, the ergodic hypothesis encounters challenges, which has aroused the researchers' strong interest. Quantum heat engine cycle has received extensive attention as a typical quantum dynamic process. From the point of view of ultra-cold atomic experiments, the quantum effect dominates the extremely low temperature experimental system. Therefore, the quantum thermal effect of the system must be considered when manipulating or further cooling the ultra-cold atoms, which is the main research content of quantum heat engine. .

In this work, the quantum integrable research group and its collaborators creatively used integrable models and low-dimensional quantum field theory research methods to analyze the quantum heat engine realized by one-dimensional contact interaction Bose gas through rigorous calculation. Loop, the analytical expression of the main parameters such as heat engine efficiency and work is obtained. Based on the characteristics of cold atom physics experiments, the author puts forward the idea of ​​realizing the quantum heat engine cycle by controlling the interaction intensity between atoms. It is theoretically confirmed that the interaction regulation can achieve a new kind of magnetothermal and autoclave effects similar to those of the well-known ones. Quantum thermal effect. Based on the analysis of the heat engine cycle, the work theoretically fully demonstrates the feasibility of the quantum heat engine with interaction control, and gives a specific experimental implementation.

In this work, Chen Yangyang, an original doctoral student of the Quantum Integrable Systems Research Group of the Institute of Precision Measurement Science and Technology Innovation, and assistant researcher Yu Yicong did the main theoretical calculations; Guan Xiwen and Adolfo del Campo were co-authors of the paper. This work was supported by the National Natural Science Foundation's key special funds, the Fund and the Ministry of Science and Technology's key focus on quantum control.

In addition, Guan Xiwen collaborated with Dr. Zou Haiyuan from the School of Physics and Astronomy, Shanghai Jiaotong University, Zhao Erhai, Professor of George Mason University, and Liu Wensheng, Professor of Li Zhengdao Institute, to study the precise solvable points and symmetric protection in the Zig-Zag quantum spin system. Topological phase, this work is supported by the National Natural Science Foundation Key Special Fund and the Ministry of Science and Technology's Quantum Control Key Project. The results were published in the Physical Review Letters.

Figure: a) Efficiency h, work W and particle number density n relationship b) Critical phase diagram and its attached different quantum heat engine cycles c) The rate of change of internal energy versus interaction intensity during the corresponding heat cycle. Here T is the temperature, m is the chemical potential, and c is the interaction strength.