Frustrated quantum magnets
Many materials exhibit magnetic ordering phenomena like ferromagnetism or antiferromagnetism at low temperatures.
However, magnetically ordered phases can be disfavoured in systems with strong quantum fluctuations and competing (aka "frustrated") magnetic interactions, where instead phases with more exotic types of order can arise.
Of particular interest are "spin liquid" phases, whose description requires novel theoretical concepts, some of them originating in quantum information theory. In recent years many new materials have been discovered which exhibit evidence of unconventional behaviour pointing towards spin-liquid physics.