Logic gates based on neuristors made from two-dimensional materials

A single biological neuron can efficiently perform Boolean operations. Artificial neuromorphic systems, on the other hand, typically require several devices to complete a single operation. Here, we show that neuristors that exploit the intrinsic polarity of two-dimensional materials can perform logic operations in a single device. XNOR gates can be made using ambipolar tungsten diselenide (WSe2), NOR gates using p-type black phosphorus, and OR and AND gates using n-type molybdenum disulfide (MoS2) of different thicknesses. To illustrate the potential of the neuristors, we fabricate logic half-adder and parity-checker circuits using a WSe2 neuristor and a MoS2 neuristor in a two-transistor two-resistor configuration, offering an area saving of 78% compared to circuits based on MoS2 gates in a traditional design. We also propose a binary neural network that is based on a three-dimensional XNOR array, which simulations show should offer an energy efficiency of 622.35 tera-operations per second per watt and a power consumption of 7.31 mW. By using two-dimensional materials with different polarities, single neuristors can act as XNOR, NOR, OR and AND logic gates.