Confinement of Superconducting Vortices in Magnetic Force Microscopy

Apr. 12 (Tue.), 4 PM, E6-2. 1st fl. #1323
Dr. Jeehoon Kim, POSTECH

Magnetic force microscope (MFM) laboratory at CALDES in IBS has constructed a 3He MFM, operating within a vector magnet with the base temperature of 300 mK and magnetic field range of 2-2-9 T in the x-y-z direction.

We demonstrated magnetic imaging capabilities at very low temperature by imaging simultaneously superconducting vortices and magnetic stripes at T= 500 mK in the ferromagnetic superconductor ErNi2B2C which has a ferromagnetic transition below Twfm=2.3 K. The direct visualization of coexistence between superconductivity and magnetism was carried out in ErNi2B2C. The vector field performance of the apparatus was also demonstrated by the creation and imaging of Abrikosov vortices within a superconducting Nb film using a vector field. For example, an in-plane field allows creating a vortex-antivortex pair which is confined through a single flux tube, and thus showing a linear potential in distance. We show an interesting contrast of interaction nature between confined and isolated vortices.​​

Contact: Eun Gook Moon, Physics Dept., (egmoon@kaist.ac.kr)