Nanoscale ferroelectric information storage based on scanning nonlinear dielectric microscopy

An investigation of ultrahigh-density ferroelectric data storage based on scanning nonlinear dielectric microscopy (SNDM) is described. For the purpose of obtaining fundamental knowledge on high-density ferroelectric data storage, several experiments on nanodomain formation in a lithium tantalate (LiTaO ₃) single crystal were conducted. Through domain engineering, a domain dot array with an areal density of 1.5 Tbit/inch ² was formed on congruent LiTaO ₃ (CLT). Sub-nanosecond (500 psec) domain switching speed also has been achieved. Next, actual information storage is demonstrated at a density of 1 Tbit/inch ². Finally, it is described that application of a very small dc offset voltage is very effective in accelerating the domain switching speed and in stabilizing the reversed nano-domain dots. Applying this offset application technique, we formed a smallest artificial nano-domain single dot of 5.1 nm in diameter and artificial nano-domain dot-array with a memory density of 10.1 Tbit/inch ² and a bit spacing of 8.0 nm, representing the highest memory density for rewritable data storage reported to date.