As research becomes an ever more globalized activity, there is growing interest in national and international comparisons of standards and quality in different countries and regions. A sign for this trend is the increasing interest in rankings of universities according to their research performance, both inside but also outside the scientific environment. New methods presented in this paper, enable us to map centers of excellence around the world using programs that are freely available. Based on Scopus data, field-specific excellence can be identified and agglomerated in regions and cities where recently highly-cited papers were published. Differences in performance rates can be visualized on the map using colors and sizes of the marks.

The second quantum technological revolution started around 1980 with the control of single quantum particles and their interaction on an individual basis. These experimental achievements enabled physicists, engineers, and computer scientists to utilize long-known quantum features—especially superposition and entanglement of single quantum states—for a whole range of practical applications. We use a publication set of 54,598 papers from Web of Science, published between 1980 and 2018, to investigate the time development of four main subfields of quantum technology in terms of numbers and shares of publications, as well as the occurrence of topics and their relation to the 25 top contributing countries. Three successive time periods are distinguished in the analyses by their short doubling times in relation to the whole Web of Science. The periods can be characterized by the publication of pioneering works, the exploration of research topics, and the maturing of quantum technology, respectively. Compared to the USA, China’s contribution to the worldwide publication output is overproportionate, but not in the segment of highly cited papers.

We present a historical study of Quantum Technology 2.0 using more than 66,000 papers from 1980 to 2020 that had been assigned to four subfields. We applied the method reference publication year spectroscopy to respective publication sets of the subfields in order to identify their historical roots and seminal papers. We found 126 of them in total, 43 in quantum metrology and sensing, 46 in quantum communication and cryptography, 42 in quantum computing, and 33 in quantum information science–with a significant overlap between subfields–which are all discussed in their relevance for the respective subfield. We compared the subfields regarding their interrelationship and distinctiveness in terms of their most influential papers and were able to deduce a common core set of five seminal publications in all four subfields.