Physics Faculty Candidate Colloquium

Tuesday, February 07, 2023 - 3:10pm to 4:00pm

DeMeritt Hall - Rm. 240

Title: Beyond Spintronics: From Classical to Quantum Information using Topological Solitons

Presenter:  Alexander P. Petrović - Nanyang Technological University, Singapore

Abstract:

Topological solitons are particle-like solutions to non-linear field equations. Since their original discovery 65 years ago in superconductors, they have been identified in systems with widely varying length and energy scales, ranging from nuclear physics to cosmology. Over the past decade, considerable attention has been devoted to magnetic skyrmions: topological solitons emerging in materials with non-collinear spin alignment. Their nanoscale dimensions, mobility, intrinsic stability and magnetoelectric coupling render them ideal for “spintronic” applications, in which information is carried by electron spins rather than charge. However, recent theoretical advances have also highlighted the exciting possibility of using skyrmions to robustly encode quantum information, by modifying the pairing symmetry in a nearby superconductor.

I will first describe the physical mechanism underpinning the emergence of skyrmions in technologically-relevant thin film magnets. Based on this principle, I will introduce a skyrmion-hosting multilayer composed of stacked iridium/iron and platinum/cobalt interfaces. Adjusting the stack architecture allows us to tune the skyrmion stability, Hall response and microwave dynamics: key requirements for spintronic devices. I will then briefly outline the concept of topological quantum computing, explaining how the crucial ingredients of a topological qubit – Majorana Zero Modes – form inside new “hybrid” topological solitons, created by coupling magnetic skyrmions to superconducting vortices. Finally, I will present the first experimental realization of skyrmion-vortex pairs and sketch out the next steps on our path towards a decoherence-resilient quantum information platform.

For Zoom link please contact Michelle.Mancini@unh.edu