Emergent gauge fields and the high temperature superconductors

Understand

The quantum entanglement of many states of matter can be represented by electric and magnetic fields, much like those found in Maxwell's theory.

• These fields "emerge" from the quantum structure of the many-electron state, rather than being fundamental degrees of freedom of the vacuum.
• I review basic aspects of the theory of emergent gauge fields in insulators in an intuitive manner.
• In metals, Fermi liquid theory relies on adiabatic continuity from the free electron state, and its central consequence is the existence of long-lived electron-like quasiparticles around a Fermi surface enclosing a volume determined by the total density of electrons, via the Luttinger theorem.