Memory-storage devices based on the current controlled motion of a series of domain walls (DWs) in magnetic racetracks promise performance and reliability beyond that of conventional magnetic disk drives and solid state storage devices(1). Racetracks that are formed from atomically thin, perpendicularly magnetized nano-wires, interfaced with adjacent metal layers with high spin-orbit coupling, give rise to narrow domain walls that exhibit a chiral Néel structure(2). These DWs can be moved very efficiently with current via chiral spin-orbit torques(2,3). Record-breaking current-induced domain wall speeds exceeding 1,000 m/sec are found in synthetic antiferromagnetic (SAF) structures(3) in which the net magnetization of the DWs is tuned to almost zero, making them “invisible”. Based on these recent discoveries, Racetrack Memory devices have the potential to operate on picosecond timescales and at densities more than 100 hundred times greater than other memory technologies. 1. S. S. P. Parkin et al. Science 320, 5873 (2008); S. S. P. Parkin and S.-H. Yang, Nature Nanotech. 10, 195 (2015). 2. K.-S. Ryu et al., Nature Nanotech. 8, 527 (2013). 3. S.-H. Yang, K.-S. Ryu and S. S. P. Parkin, Nature Nanotech.10, 221 (2015). 4. S. S. P. Parkin, Phys. Rev. Lett. 67, 3598 (1991).