Modeling the Stability Diagram and Electrical Conductance of a Tunneling Resonance System Based on a Carbon Nanotube Quantum Dot

Abstract

Carbon nanotubes (CNTs) and CNT-based quantum dots (CNTQDs) hold significant promise for nextgeneration quantum and digital computing devices. This study presents a comprehensive theoretical analysis of the electronic properties of CNTs and CNTQDs, focusing on their stability diagrams and electrical conductance characteristics. Using the constant interaction model (CIM) and Green's function formalism within the Keldysh framework, we derive the quantized energy levels of the CNTQDs, evaluate their Coulomb blockade phenomena, and deduce the electric conductance through the CNTQDs. This study illustrates how valley and spin degeneracy lead to the creation of four blockade diamonds as well as four conductance peaks per quantized energy level. The stability diagrams help in designing stable transistors and qubits that exhibit a voltage map that can be used for control in these devices.