Bichromatic field generation from double-four-wave mixing in a double-electromagnetically induced transparency system

We demonstrate the double electromagnetically induced transparency (double-EIT) and double four-wave mixing (double-FWM) based on a new scheme of non-degenerate four-wave mixing (FWM) involving five levels of a cold 85Rb atomic ensemble, in which the double-EIT windows are used to transmit the probe field and enhance the third-order nonlinear susceptibility. The phase-matching conditions for both four-wave mixings could be satisfied simultaneously. The frequency of one component of the generated bichromatic field is less than the other by the ground-state hyperfine splitting (3GHz). This specially designed experimental scheme for simultaneously generating different nonlinear wave-mixing processes is expected to find applications in quantum information processing and cross phase modulation. Our results agree well with the theoretical simulation.Comment: Accepted by NJ

Visualization Analysis of Food Safety Traceability System: Based on Bibliometrics

In order to summarize the evolution of food safety traceability system research in globally, 1369 research paper published in the period of 2004 to 2022 are retrieved using the words: food and traceability from the Web of Science Core Collection database and are test mined for the number of research papers, authors, countries, institutions using statistical and bibliometric indicators. Moreover, data visual analysis is carried out by plotting knowledge maps of keywords. The results show that there has been increasing interest in food research, and the number of publications about food safety traceability exhibits a growth trend. The most studied country is China that has published 331 papers with the H index ranks second. In terms of authorship, the research team mostly works with productive author cooperation in this field with cross-border and cross-regional cooperation. In terms of keywords cooccurrence, Smart contracts, blockchain, the Internet, traceability technology, and information transparency have been the research hotspots in this field in recent years. The research topics gather on the applicability of traceability technology, participation of social subjects, study on food adulteration and origin traceability based on stable isotope ratio and multi-element analysis, and solving the problem of coding confusion