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 …

This is an introductory review of the physics of quantum spin liquid states. Quantum
magnetism is a rapidly evolving field, and recent developments reveal that the ground states …

This article reviews the physics of high-temperature superconductors from the point of view
of the do** of a Mott insulator. The basic electronic structure of cuprates is reviewed …

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 …

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 …

Spin liquids are collective phases of quantum matter that have eluded discovery in
correlated magnetic materials for over half a century. Theoretical models of these enigmatic …

Two gapped quantum ground states in the same phase are connected by an adiabatic
evolution which gives rise to a local unitary transformation that maps between the states. On …

The spin ice materials, including Ho 2 Ti 2 O 7 and Dy 2 Ti 2 O 7, are rare-earth pyrochlore
magnets which, at low temperatures, enter a constrained paramagnetic state with an …

A quantum spin liquid is an exotic quantum state of matter in which spins are highly
entangled and remain disordered down to zero temperature. Such a state of matter is …

At sufficiently low temperatures, condensed-matter systems tend to develop order. A notable
exception to this behaviour is the case of quantum spin liquids, in which quantum …