We learned that there are three states of matter. When cooled down, gas will become liquid, which will eventually turn into solid at a low enough temperature. But when quantum mechanics are in play, things become much more interesting. For example, helium does not become solid even at temperatures close to absolute zero. Instead, it remains in a liquid state due to strong quantum effects. Such quantum fluids can be also found in a gas of cold atoms or neutron stars, but they are very rare in nature. However, in recent years, there have been extensive efforts from condensed matter physicists to find another example of quantum fluid called quantum spin liquid in ordinary-looking magnets. Such a spin system is described by a macroscopic quantum state in which many spins are all highly entangled, a very useful property for building a quantum computer. In this talk, I will give a brief overview of quantum spin liquid research and present recent advances in the search for a quantum spin liquid phase in materials with strong spin-orbit coupling.
