Construction and electrical control of ultrahigh-density organic memory arrays at cryogenic temperature

Investigation into the structural and magnetic properties of organic molecules at cryogenic temperature is beneficial for reducing molecular vibration and stabilizing magnetization, and is of great importance for constructing novel spintronics devices of better performance and scaling the device size down to nanoscale. In order to explore the possibility of fabricating molecule-based memory chips of ultrahigh density, two-dimensional close-packed molecular arrays with carboxylic acid molecules were constructed in the current work and the magnetic properties in a low-temperature scanning tunneling microscope were also investigated. The results demonstrated that each nonmagnetic molecule can be controllably and independently switched into a stable spin-carrying state at 4 K by applying a voltage pulse with atomic resolution. Benefiting from the small size of a single molecule as the basic storage bit, the two-dimensional molecular arrays allowing controllable electrical manipulations on each molecule can behave as a platform of memory chip with an ultrahigh storage density of ∼320 terabytes (Tb) (or ∼2500 terabits) per square inch. This work highlights the potential and advantage of employing organic molecules in developing future cryogenic information storage techniques and devices at nanoscale.