Ultra-low power circuits using graphene p–n junctions and adiabatic computing

Abstract

Recent works have proven the functionality of electrostatically controlled graphene p–n junctions that can serve as basic primitive for the implementation of a new class of compact graphene-based reconfigurable multiplexer logic gates. Those gates, referred as RG-MUXes, while having higher expressive power and better performance w.r.t. standard CMOS gates, they also have the drawback of being intrinsically less power/energy efficient.In this work we address this problem from a circuit perspective, namely, we revisit RG-MUXes as devices that can operate adiabatically and hence with ultra-low (ideally, almost zero) power consumption. More specifically, we show how to build basic logic gates and, eventually, more complex logic functions, by appropriately interconnecting graphene-based p–n junctions as to implement the adiabatic charging principle.We provide a comparison in terms of power and performance against both adiabatic CMOS and their non-adiabatic graphene-based counterparts; characterization results collected from SPICE simulations on a set of representative functions show that the proposed ultra-low power graphene circuits can operate with 1.5–4 orders of magnitude less average power w.r.t. adiabatic CMOS and non-adiabatic graphene counterparts respectively. When it comes to performance, adiabatic graphene shows 1.3 (w.r.t. adiabatic CMOS) to 4.5 orders of magnitude (w.r.t. non-adiabatic technologies) better power-delay product.