ENHANCED SPIN INTERACTIONS IN DIGITAL MAGNETIC HETEROSTRUCTURES

A new heterostructure is developed in which fractional monolayers of m agnetic ions are introduced ''digitally'' within a semiconductor quant um well. Rearranging moments within two-dimensional (2D) planes provid es additional control over their interactions, yielding tunable two-le vel electronic systems in which spin splittings are significantly larg er than inhomogeneous linewidths in modest magnetic fields. Femtosecon d-resolved electronic and magnetic spectroscopies reveal spin-flip sca ttering dependent only on the Zeeman energy but not the local magnetic environment, and long-lived dynamic magnetizations.