Our paper on Unconventional magnetism mediated by spin-phonon-photon coupling has been published in Nature Communications!

Magnetic order typically emerges from short-range exchange interactions between electronic spins. In this work, we demonstrate theoretically the emergence of a biquadratic long-range interaction between spins mediated by their coupling to phonons hybridized with vacuum photons into polaritons.

This resulting ordered state, enabled by the exchange of virtual polaritons between spins, is reminiscent of superconductivity mediated by the exchange of virtual phonons. The biquadratic nature of the spin-spin interaction promotes ordering without favoring ferro- or antiferromagnetism, and makes the phase transition to magnetic order a first-order transition, unlike in conventional magnets.

This leads to unique features:

  • Large magnetization develops abruptly on lowering the temperature
  • Enables magnetic memories with ultralow-power thermally-assisted writing
  • High data stability
  • In-situ static control via photons

These properties make this unconventional spin-spin interaction and magnetism highly promising for novel scientific and technological opportunities.

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