Quantum transport in a mesoscopic ring: Evidence of an OR gate

TL;DR

This paper demonstrates how a mesoscopic ring can function as an OR logic gate by using magnetic flux and gate voltages, with theoretical calculations showing clear logical output based on input voltages.

Contribution

The study introduces a theoretical model of a mesoscopic ring acting as an OR gate using magnetic flux and gate voltages, employing tight-binding and Green's function methods.

Findings

High output current when one or both inputs are high at flux φ=φ₀/2

Low output current when both inputs are low

Potential application in electronic logic gate design

Abstract

We explore OR gate response in a mesoscopic ring threaded by a magnetic flux $\phi$. The ring is symmetrically attached to two semi-infinite one-dimensional metallic electrodes and two gate voltages, viz, $V_a$ and $V_b$, are applied in one arm of the ring which are treated as the two inputs of the OR gate. All the calculations are based on the tight-binding model and the Green's function method, which numerically compute the conductance-energy and current-voltage characteristics as functions of the gate voltages, ring-to-electrodes coupling strengths and magnetic flux. Our theoretical study shows that, for $\phi=\phi_0/2$ ($\phi_0=ch/e$, the elementary flux-quantum) a high output current (1) (in the logical sense) appears if one or both the inputs to the gate are high (1), while if neither input is high (1), a low output current (0) appears. It clearly demonstrates the OR gate behavior and this aspect may be utilized in designing the electronic logic gate.