Manipulation of electrons in a solid through transmitting, storing, and switching is the fundamental basis for the microelectronic devices. Recently, the electroresistance effect in the ferroelectric capacitors has provided a novel way to modulate the electron transport by polarization reversal. Here, we demonstrate a giant electroresistive ferroelectric diode integrating a ferroelectric capacitor into two-dimensional electron gas (2DEG) at oxide interface. As a model system, we fabricate an epitaxial Au/Pb(Zr<inf>0.2</inf>Ti<inf>0.8</inf>)O<inf>3</inf>/LaAlO<inf>3</inf>/SrTiO<inf>3</inf> heterostructure, where 2DEG is formed at LaAlO<inf>3</inf>/SrTiO<inf>3</inf> interface. This device functions as a two-terminal, non-volatile memory of 1 diode-1 resistor with a large I<inf>+</inf>/I<inf>-</inf> ratio (>10<sup>8</sup> at ±6 V) and I<inf>on</inf>/I<inf>off</inf> ratio (>10<sup>7</sup>). This is attributed to not only Schottky barrier modulation at metal/ferroelectric interface by polarization reversal but also the field-effect metalinsulator transition of 2DEG. Moreover, using this heterostructure, we can demonstrate a memristive behavior for an artificial synapse memory, where the resistance can be continuously tuned by partial polarization switching, and the electrons are only unidirectionally transmitted. Beyond non-volatile memory and logic devices, our results will provide new opportunities to emerging electronic devices such as multifunctional nanoelectronics and neuromorphic electronics.
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