Our paper on Electrostatic nature of cavity-mediated interactions between low-energy matter excitations has been published as a Letter and Editor’s Suggestion in Physical Review B!

The use of cavity quantum electrodynamics to modify material properties has gained significant attention, but general results providing intuitive understanding and limitations are still scarce. In this work, we provide such a result for effective interactions between low-energy matter excitations induced by their coupling to the cavity electromagnetic field.

Our key finding: The induced interactions are purely electrostatic in nature and are thus fully described by the EM Green’s function evaluated at zero frequency. This has important implications:

  • Reduced models with one or a few cavity modes can easily give misleading results
  • A multimode description is necessary for cavity engineering of matter systems
  • The long-wavelength electromagnetic modes don’t contribute to the effective interactions

These findings provide important guidelines for understanding and designing cavity-modified material properties and call for reevaluation of some previous theoretical predictions based on single-mode models.

This work was done in collaboration with Petros-Andreas Pantazopoulos, Akashdeep Kamra, and Francisco J. García-Vidal.