Ferromagnets are able to store digital information as "0" and "1" using different orientation of magnetic moments that could be pictured as small compasses (image a). This principle works in a broad variety of memory devices from kilobyte magnetic cards to terabyte hard disks. Ferromagnetic memory devices can't be placed near to another magnets or devices producing strong magnetict field – magnetic moments in memory would be reoriented resulting in loss of the stored information (image b). In collaboration with labs in Berkeley and Barcelona we demostrated that it is possible to use another type of materials for storing information, an antiferromagnet. Antiferromagnetic materials are magnetic within them but their microscopic magnetic moments from individual atoms alternates with opposite orientation (image c). Due to this antiparalel configurationof antiferromagnets (and unlike from the paralel configuration in ferromagnets) the information in antiferromagnetic memory devices is insensitive to outer magnetic fields (image d).
