# NOT gate response in a mesoscopic ring: An exact result

## TL;DR

This paper demonstrates a theoretical model of a mesoscopic ring functioning as a NOT gate, showing that magnetic flux and gate voltage can control current to mimic logical inversion, useful for nanoelectronic logic devices.

## Contribution

It provides an exact theoretical analysis of NOT gate behavior in a mesoscopic ring using tight-binding and Green's function methods, highlighting flux-induced logical switching.

## Key findings

- High output current at half flux quantum when input is low
- Low output current at half flux quantum when input is high
- Potential application in nanoelectronic logic gate design

## Abstract

We explore NOT gate response in a mesoscopic ring threaded by a magnetic flux $\phi$. The ring is attached symmetrically to two semi-infinite one-dimensional metallic electrodes and a gate voltage, viz, $V_a$, is applied in one arm of the ring which is treated as the input of the NOT gate. 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 ring-to-electrodes coupling strength, magnetic flux and gate voltage. 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 the input to the gate is low (0), while a low output current (0) appears when the input to the gate is high (1). It clearly exhibits the NOT gate behavior and this aspect may be utilized in designing an electronic logic gate.