News from our correspondent (by Wen Caifei) Recently, Lin Xiao, a distinguished researcher of West Lake University, teamed up with Wu Congjun, a chair professor of West Lake University, and Wang Zhiwei, an associate professor of Beijing University of Technology, and reported for the first time the zero magnetic field superconducting diode effect and the superconducting interference pattern formed by quantizing the magnetic flux in the single superconducting device CsV3Sb5 (cesium vanadium antimony, hereinafter referred to as CVS) material, The existence of time reversal symmetry breaking, superconducting domains, and possible loop superfluids in CVS materials are revealed. Relevant research results were published in Nature.
Bamboo weaving is one of the handicrafts of Chinese intangible cultural heritage. The hexagonal eye composed of regular hexagon and triangle is the most common pattern of bamboo weaving. It has a nickname: cage. Cage superconductive material refers to the material whose "structure" (arrangement of atoms) has cage periodicity and superconductivity. This material has many unique physical properties due to its unique crystal configuration, rich and colorful electronic structure, strange and interesting electronic order, and has become the focus in the field of superconductors.
Lotte, who is engaged in postdoctoral research in Lin Xiao Laboratory, proposed a bold guess: will CVS, a new superconducting material, naturally possess the "talent" of diode under zero magnetic field conditions? The team finally confirmed the authenticity of the zero magnetic field superconducting diode effect observed in the experiment, which to some extent proved that the time reversal symmetry of the CVS material in the superconducting state was broken.
In the experiment, they accidentally saw a graceful "dance" - the periodic oscillation pattern of the superconducting critical current changing with the magnetic field. By repeatedly measuring the temperature rise and fall of the CVS device, they found that the polarity of the zero magnetic field superconducting diode and the superconducting interference pattern would change, which fully confirmed the assumption of superconducting domains. Wu Congjun's team has built a theoretical model for the formation of superconducting loops in superconducting domains based on the existing experimental results. The theoretical calculations given are qualitatively consistent with the experimental results, providing a preliminary theoretical image.
This work reveals for the first time some characteristics of the superconducting material CVS that have never been discovered before, and provides important experimental evidence and experimental direction for the future research of cage superconducting materials and superconducting quantum electronics.
Relevant paper information:
https://doi.org/10.1038/s41586-024-07431-y
