  Quantum computers have made extraordinary progress over the past decade, and
significant milestones have been achieved along the path of pursuing universal
fault-tolerant quantum computers. Quantum advantage, the tipping point
heralding the quantum era, has been accomplished along with several waves of
breakthroughs. Quantum hardware has become more integrated and architectural
compared to its toddler days. The controlling precision of various physical
systems is pushed beyond the fault-tolerant threshold. Meanwhile, quantum
computation research has established a new norm by embracing industrialization
and commercialization. The joint power of governments, private investors, and
tech companies has significantly shaped a new vibrant environment that
accelerates the development of this field, now at the beginning of the noisy
intermediate-scale quantum era. Here, we first discuss the progress achieved in
the field of quantum computation by reviewing the most important algorithms and
advances in the most promising technical routes, and then summarizing the
next-stage challenges. Furthermore, we illustrate our confidence that solid
foundations have been built for the fault-tolerant quantum computer and our
optimism that the emergence of quantum killer applications essential for human
society shall happen in the future.
