Phase and Thermal Driven Transport across T-Shaped Double Quantum Dot Josephson Junction

TL;DR

This paper investigates how phase and thermal biases influence electron transport in a T-shaped double quantum dot Josephson junction, revealing the interplay between supercurrent, quasi-particle current, and thermophase effects.

Contribution

It introduces a detailed analysis of thermally and phase-driven transport in a T-shaped double quantum dot Josephson junction, highlighting the role of interdot hopping and quantum dot energy levels.

Findings

Interdot hopping affects Andreev bound states and supercurrent.

Thermal bias induces a quasi-particle current and thermophase effects.

Open circuit conditions show phase-driven supercurrent compensates thermally induced currents.

Abstract

The phase and thermal driven transport properties of the T-shaped uncorrelated double quantum dot Josephson junction are analyzed by using Keldysh non-equilibrium Green's function equation of motion technique. In this setup, we have shown that the side-attached quantum dot provides an additional route for electron transmission which is affecting the transport properties by adjusting the interdot hopping between the main dot and the side dot. We began with investigating the impact of interdot hopping on Andreev bound states and Josephson supercurrent. When a small thermal bias is applied across the superconducting leads, the system exhibits a finite thermal response which is primarily due to the, thermally induced, quasi-particle current. The behavior of the Josephson supercurrent and the quasi-particle current flowing through the quantum dots is examined for various interdot hopping and thermal biasing. Finally, the system is considered in an open circuit configuration where the thermally driven quasi-particle current is compensated by the phase-driven Josephson supercurrent and the thermophase effect is observed. The effect of interdot hopping and the position of quantum dot energy level on the thermophase Seebeck coefficient is investigated