ATOMIC-BEAM STUDY OF A SUPERCONDUCTORS MAGNETIC VORTEX LATTICE

We have developed an atomic beam technique for studying magnetic vorti ces and vortex lattices of superconductors. Atoms moving near a superc onductor's surface see a fluctuating magnetic field as they pass vorti ces. This field may drive magnetic resonance transitions between hyper fine states. Measuring the magnetic resonance transition probability a s a function of atom velocity probes the vortex lattice autocorrelatio n function. We demonstrate this technique by studying the vortex latti ce of a niobium film sample and measuring the sample's penetration dep th. We also identify a systematic problem that we think thwarted an ea rlier attempt to experimentally realize this technique.