Patent ID: 8068405

Claim:
A method for data storage, the method comprising: applying a first voltage between a tip and an electrode, the applying comprising forming a polarized domain in a ferroelectric (FE) material, the FE material between 1 nanometer (nm) and 50 nm in thickness; applying a second voltage through the tip, the applying the second voltage comprising generating a first current between the tip and the electrode, wherein: the first current is responsive to an orientation of the polarized domain; and the second voltage is a lower voltage than the first voltage, and applying the second voltage does not change the orientation of the polarized domain; applying a third voltage through the tip, the applying the third voltage comprising generating a second current between the tip and the electrode, wherein: the second current is responsive to the orientation of the polarized domain; the third voltage is a lower voltage than the first voltage; applying the third voltage does not change the orientation of the polarized domain; and applying the second voltage and applying the third voltage comprise applying bipolar pulses; measuring the first current; measuring the second current; and determining the orientation of the polarized domain, the determining based upon a ratio, wherein the ratio is selected from the group consisting of the quotient produced by dividing the measurement of the first current by the measurement of the second current and the quotient produced by dividing the measurement of the second current by the measurement of the first current.