Kilohertz magnetic field focusing in a pair of metallic periodic-ladder structures.

Here, we show, analytically and numerically, that in a pair of metallic periodic-ladder structures placed with a central gap, the normally incident magnetic field is focused on a spot of 3 mm (0.6 × 10-5 free space wavelength) full width at half maximum at a 1 mm distance away at 600 kHz. The ladder structures are designed by exploiting the curl of the induced current at each unit cell in the periodic structure. This investigation paves the way for kilohertz magnetic field manipulations. [ABSTRACT FROM AUTHOR]