Ongoing experiments in the lab are related to:
Skyrmions in magnetic thin films. There has been a recent flurry of activity to realize and measure these topologically protected, mesoscopic scale, magnetic domains. We use low temperature magnetic force microscopy (MFM) to characterize the host films as well as to image and manipulate the skyrmions themselves.
- Vortices in superconductors. We use low temperature magnetic force microscopy (MFM) to both image and to manipulate individual vortices trapped on twin boundaries, which are a common planar defect in many materials. This allows us to study the interplay between disorder, elasticity and interactions in reduced dimensions and to test an extensive body of theoretical work. This is important because vortices and vortex matter share many features with a wide variety of systems across different fields including polymers, magnetic domain walls, strongly driven fluids, friction, and spin-glasses.
- Novel materials. One of the strengths of scanned probes is that they can be rapidly applied to a new material without much device development. For example, we are developing and implementing methods to study the penetration depth λ in superconductors. This is important because while λ encodes much information about the superconducting state, it is notoriously hard to measure. In addition, we are able to gain information about the unavoidable disorder in samples by mapping the locations of superconducting vortices which tend to be attracted to defects.