Figure 3: Demonstration of two-level memory.
(a) Two-level switch of αE between positive and negative. E pulses of ±4 kVcm−1 were applied to fully reverse polarization between +Ps and –Ps so that αE switches between positive and negative. Each E pulse lasts for 1 s. (b) Two-level switch of αE between high and low values. E pulse of +4 kVcm−1 was used to reach +Ps and −3 kVcm−1 was applied to partially reverse ferroelectric domains. As a result, αE switches between high and low values.
