BACKGROUND Years ago, Lev Landau taught us how to think about distinct phases of
matter through an order parameter that characterizes the symmetry-broken state relative to …

Quantum spin liquids may be considered'quantum disordered'ground states of spin systems,
in which zero-point fluctuations are so strong that they prevent conventional magnetic long …

What are topological phases of matter? First, they are phases of matter at zero temperature.
Second, they have a nonzero energy gap for the excitations above the ground state. Third …

The defining problem in frustrated quantum magnetism, the ground state of the nearest-
neighbor S= 1/2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all …

We analyze the effect of quenched disorder on spin-1/2 quantum magnets in which
magnetic frustration promotes the formation of local singlets. Our results include a theory for …

Quantum spin liquids are an exciting playground for exotic physical phenomena and
emergent many-body quantum states. The realization and discovery of quantum spin liquid …

Frustration in magnetic materials arising from competing exchange interactions can prevent
the system from adopting long-range magnetic order and can instead lead to a diverse …

Quantum spin liquids form a novel class of matter where, despite the existence of strong
exchange interactions, spins do not order down to the lowest measured temperature …

BACKGROUND Our world is very rich. One aspect of its richness is reflected in the existence
of many different phases of matter. More than half a century ago, Landau developed a theory …

The long fascination that antiferromagnetic materials has exerted on the scientific community
over about a century has been entirely renewed recently with the discovery of several …