Achieving Entire\nSeven Fundamental Boolean Logic Operations\nin a Two-Terminal Li-Based Memristor

Conventional logic operations transmitting data between\nprocessing\nand the memory unit inevitably result in a “memory wall”\nand energy consumption dilemmas. The memristor provides an alternative\nsolution at the device level by integrating logic operations and memory\nfunctions, however, a combination of multistage operations in memristors\nis required to achieve fundamental Boolean logic calculations, especially\nfor XOR/XNOR. In this work, we implement the XOR/XNOR through leveraging\nbifunctional oxygen-containing Ti thin films as both current collectors\nand Li-reservoirs in a two-terminal Li-based memristor, i.e., ITO/Nb<sub>2</sub>O<sub>5</sub>/LiCoO<sub>2</sub>/Ti. When Li-ions are inserted\ninto oxygen-containing Ti under reversed voltage and partially reduce\nthe high-valence Ti, the subsequent postsynaptic current exceeds the\nthreshold, thereby realizing the XOR/XNOR logic operations. Therefore,\nthe entire seven fundamental Boolean logic operations can be achieved\nin an individual device, featuring biological-like synaptic plasticity\nwithout redundant circuit design. Through electrochemical modulation\nof pulse parameters, the artificial synapse demonstrates versatile\ntypes of short-term potentiation, encompassing pair-pulse facilitation,\nspike-voltage-dependent plasticity, and spike-rate-dependent-plasticity\n(SRDP). The SRDP displays properties analogous to a high-pass filter\nas discernible distinction of current response within and beyond the\nfrequency of 1 Hz. Furthermore, the Physiological functions of Ebbinghaus’\nmemory curves and Pavlov’s classical conditioning experiment\nare emulated on this single memristor based on the principles of long-term\npotentiation.