Collective excitations and instability of an optical lattice due to unbalanced pumping

TL;DR

This paper investigates how unbalanced optical pumping influences collective excitations and stability in a one-dimensional optical lattice, revealing the emergence of traveling density waves and potential destabilization.

Contribution

It presents a self-consistent solution to coupled particle-field equations showing how asymmetric pumping induces collective oscillations and lattice instability.

Findings

Traveling density wave-like oscillations occur with asymmetric pumping.

Lattice destabilization can happen as the system size or pump asymmetry increases.

Optomechanical coupling leads to long-range interactions affecting stability.

Abstract

We solve self-consistently the coupled equations of motion for trapped particles and the field of a one-dimensional optical lattice. Optomechanical coupling creates long-range interaction between the particles, whose nature depends crucially on the relative power of the pump beams. For asymmetric pumping, traveling density wave-like collective oscillations arise in the lattice, even in the overdamped limit. Increasing the lattice size or pump asymmetry these waves can destabilize the lattice.