  The second quantum revolution has been producing groundbreaking scientific
and technological outputs since the early 2000s; however, the scientific
literature on the impact of this revolution on the industry, specifically on
start-ups, is limited. In this paper, we present a landscaping study with a
gathered dataset of 441 companies from 42 countries that we identify as quantum
start-ups, meaning that they mainly focus on quantum technologies (QT) as their
primary priority business. We answer the following questions: (1) What are the
temporal and geographical distributions of the quantum start-ups? (2) How can
we categorize them, and how are these categories populated? (3) Are there any
patterns that we can derive from empirical data on trends? We found that more
than 92% of these companies have been founded within the last 10 years, and
more than 50% of them are located in the US, the UK, and Canada. We categorized
the QT start-ups into six fields: (i) complementary technologies, (ii) quantum
computing (hardware), (iii) quantum computing
(software/application/simulation), (iv) quantum cryptography/communication, (v)
quantum sensing and metrology, and (vi) supporting companies, and analyzed the
population of each field both for countries, and temporally. Finally, we argue
that low levels of quantum start-up activity in a country might be an indicator
of a national initiative to be adopted afterwards, which later sees both an
increase in the number of start-ups, and a diversification of activity in
different QT fields.
