Topological phonon-magnon coupling in atomically thin antiferromagnet

Check out our new results on Nano Letters! We have observed coherent hybridization of magnons and phonons first ever in monolayer antiferromagnet FePSe3 by cavity-enhanced magneto-Raman spectroscopy. The coupling remains robust even in zero magnetic field down to 2D limit in a single atomic layer. We also discovered theoretically that such magnon-phonon hybridization enables nontrivial band inversion between longitudinal and transverse optical phonons and guarantee magnetic-field-controlled topological phase transition. The 2D topological magnon–phonon hybridization would potentially offer a new route toward quantum phononics and magnonics with an ultrasmall footprint.

Rice team looks into macroscopic quantum entanglement

Hanyu and collaborators received $2.5M support from the Keck foundation and Rice University to search for exotic quantum states formed by all the spins in a visible piece of material. The phenomenon, called “quantum squeezing”, describes the entanglement of spins that allows their quantum fluctuation to cancel each other, resulting in higher precision in certain measurements than what is expected from Heisenberg uncertainty principle. Usually in materials with many atoms, such entanglement should diminish very quickly, but theoretical predictions and experimental results indicating the strong interaction among spins may actually stabilize the quantum state and automatically reestablish the squeezing at very low temperatures. The Rice team plans to push the limit of their tools in this unexplored territory. More details of the project can be found in the news report here.