Effective holographic theory of charge density waves

Understand

We use Gauge/Gravity duality to write down an effective low energy holographic theory of charge density waves.

• We consider a simple gravity model which breaks translations spontaneously in the dual field theory in a homogeneous manner, capturing the low energy dynamics of phonons coupled to conserved currents.
• We first focus on the leading two-derivative action, which leads to excited states with non-zero strain.
• We show that including subleading quartic derivative terms leads to dynamical instabilities of AdS$_2$ translation invariant states and to stable phases breaking translations spontaneously.