History teaches us that fundamental science is critical to the development of revolutionary technologies. In the early 1600s, Galileo improved the design of telescopes to advance astronomical observations, but those same devices also paved the way for ocean voyage. In the early 20th century, Einstein’s curiosity in space–time, energy and matter triggered his general theory of relativity that in turn led to satellite navigation. Galileo and Einstein were both primarily motivated by fundamental science, but their achievements also directly led to important technologies that have had far-reaching consequences in everyday life.

Fundamental science is critical when it comes to developing new technologies – not only because fundamental science may directly lead to great inventions but also because it has a deeper influence in shaping thinking. It makes one ask probing questions, forces one to critically check the most basic principles, and pushes one to think in the most creative and revolutionary way.

Besides leading to new technologies, fundamental science also exhibits an intrinsic beauty. Human beings have always been fascinated by fundamental questions such as how the universe was born, how matter forms, what kinds of matter exist and how consciousness emerges.

Although most of these questions remain mysterious, progress has been made in understanding them. Indeed, such understanding often exhibits great elegance. James Clerk Maxwell, for example, unified the phenomena of electricity and magnetism into a set of simple equations. Despite their simplicity, these equations display rather neat structures, highlighting the symmetry between the two.

Beauty and applications

Theoretical condensed-matter physics is one of the areas of fundamental science that has intrinsic beauty and the potential for applications. This area focuses on possible forms of macroscopic systems and how different forms convert into each other. For example, one gram of water molecules can be viewed as a macroscopic system and it can take up various forms: ice, water or vapour. These different forms are also called the different phases of water and the process for the water to go from one phase into another is called a phase transition.

Condensed-matter physics is the subject that investigates phases and phase transitions. More concretely, it looks at the rationalization, detection, realization, exploration, characterization and classification of phases as well as transitions among them. As one central goal of science is to explain observed phenomena, a major effort in condensed-matter physics is devoted to the rationalization of experiments on various materials. Typical questions in this direction include – but are not limited to – why certain materials are insulating whereas others appear to be metallic.

In many cases, condensed-matter theorists also need to propose methods to realize and detect various phases. A related field under intense study is how to realize and detect Majorana fermions in solid-state materials. These particles are their own antiparticles and possess potential applications in quantum computing.

The exploration of new phases of matter is particularly exciting and such breakthroughs can often significantly boost the field. For example, researchers used to think all systems will equilibrate thermally, but recently, phases that never fall into -thermal equilibrium have been found. These so-called many-body localized phases are now being widely studied.

When a new concept is first proposed, scientists may not know how to characterize it, so it is sometimes important to propose new ways to do so. Historically, researchers used symmetries to characterize phases, but it is now better appreciated that quantum entanglement needs to be incorporated into the characterization too. Finally, after collecting and understanding the plethora of phases, it will be important to classify all of them according to some principle. Such classifications yield a unified understanding of the “zoo” of possible phases.

One example I have worked on is quantum spin liquids – a phase that displays an intricate interplay between quantum entanglement and symmetry. This work is one of the first systematic studies of 3D symmetry-enriched long-range entangled phases. Based on this work, I proposed a new way to characterize topological crystalline insulators, which are phases that have non-trivial topological properties in the presence of symmetries. The new characterization is more general than the conventional method, and, interestingly, it is also simpler. More recently, my colleagues and I have proposed explanations for the remarkable experimental discoveries of unconventional insulating and superconducting behaviours in twisted bi-layer graphene.

Long-term vision

The importance of fundamental science is recognized by many countries. Yet due to basic science’s lack of immediate applications, it has largely been overlooked in traditional Chinese culture. The general public in China often cares more about issues that tackle questions about everyday life than fundamental questions. But the country needs to devote more resources to fundamental research.

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The 2018 Physics World Special Report on China is out now

It may be impossible for everyone in a country to be a researcher in fundamental science, but a good environment for fundamental science helps the country shape its spirit. When the entire country possesses a scientific spirit, it will be hard to stop the creation of original technologies. I hope more Chinese scientists will become interested in fundamental research and together we can make great discoveries. In the long run, I hope the fundamental sciences we study will yield powerful technology. More importantly, through all our efforts, I hope we can contribute to the spirit of China in a positive way, however minor it may appear in the short term.

• This article is the winning entry in the inaugural Physics World science-communication award focusing on the advances China is making in science, technology, engineering and medicine.