▎ 摘　　要

In this paper, an ultra-compact graphene-based plasmonic structure for implementing all two-input/one-output logical operations utilizing the electro-optical effect is proposed. The plasmonic waveguides are composed of graphene nano-ribbons located on a dielectric/metal layers stack. The switching mechanism is based on locally changing the chemical potential of the graphene by applying external voltage. Setting the chemical potential of 0.95 eV allows surface plasmon polaritons (SPPs) to travel in the waveguide while decreasing the chemical potential to 0.1 eV prevents the propagation of SPPs. Using the finite-difference time-domain method, two-input/one-output logic gates, including AND, OR, XOR, NAND, NOR, and XNOR as well as two logical functions of A center dot BMODIFIER LETTER PRIME and A + BMODIFIER LETTER PRIME are simulated. According to the simulation results, the minimum extinction ratios of 11.14 dB, 23.75 dB, and 10.52 dB are achieved at the wavelength of 16 mu m for the logical operations of AND/NOR/A center dot BMODIFIER LETTER PRIME, OR/NAND/A + BMODIFIER LETTER PRIME, and XOR/XNOR, respectively. The total size of the device is less than 0.75 mu m(2). Thereby, the proposed device, with advantages like ultra-compact size, high extinction ratios, and simple functionality, is a promising choice for use in on-chip digital computational circuits and paves the way for the design of future integrated photonic devices.