A kilobyte rewritable atomic memory

The control of atomic vacancies on a chlorine-terminated Cu(100) surface by means of a scanning tunnelling microscope tip makes it possible to construct a rewritable atomic memory of over a kilobyte in size with an information density as high as 502 terabits per square inch. The advent of devices based on single dopants, such as the single-atom transistor 1 , the single-spin magnetometer 2 , 3 and the single-atom memory 4 , has motivated the quest for strategies that permit the control of matter with atomic precision. Manipulation of individual atoms by low-temperature scanning tunnelling microscopy 5 provides ways to store data in atoms, encoded either into their charge state 6 , 7 , magnetization state 8 , 9 , 10 or lattice position 11 . A clear challenge now is the controlled integration of these individual functional atoms into extended, scalable atomic circuits. Here, we present a robust digital atomic-scale memory of up to 1 kilobyte (8,000 bits) using an array of individual surface vacancies in a chlorine-terminated Cu(100) surface. The memory can be read and rewritten automatically by means of atomic-scale markers and offers an areal density of 502 terabits per square inch, outperforming state-of-the-art hard disk drives by three orders of magnitude. Furthermore, the chlorine vacancies are found to be stable at temperatures up to 77 K, offering the potential for expanding large-scale atomic assembly towards ambient conditions.