IQUIST Young Researchers Seminar: "When Magnons Meet Quantum Optics: From Single Quanta to Itinerant-Magnon Phase-Space Tomography," Jinho Lim, Hoffmann Group

"When Magnons Meet Quantum Optics: From Single Quanta to Itinerant-Magnon Phase-Space Tomography" 

Abstract: Quantum magnonics now encompasses approaches ranging from the detection and control of individual quanta in stationary magnon modes to phase-space state tomography and control of propagating magnons. In this presentation, I will first provide a brief overview of the development of quantum magnonics over the past decade. Second, I will introduce the singleshot heterodyne detection and accompanying Husimi Q-function tomography that we  developed for itinerant magnons. Finally, I will discuss the Kerr-type nonlinear evolution of  itinerant magnon states, in which we observe the evolution from a Gaussian coherent-state distribution to a crescent-shaped non-Gaussian phase-space distribution driven by magnon Kerr interactions. The Kerr coefficient is determined from the Kerr-induced phase evolution and is approximately six orders of magnitude larger than values reported for stationary magnons in conventional cavity-magnonic systems. This work may offer opportunities for information processing with itinerant magnons, such as phase encoding, and illustrates how a quantumoptical framework for phase-space state tomography can be applied to itinerant collective excitations in condensed-matter systems.

Bio:  Jinho Lim is a postdoctoral researcher in Axel Hoffmann’s group, where he studies quantum magnonics.