22. 04. 2024

Hidden Symmetry Revealed

Hidden Symmetry Revealed

In a recent letter by Peter Zalom from FZU, Martin Žonda, and Tomáš Novotný from our department, a novel approach to understanding interacting quantum dots coupled to multiple superconducting leads, based on a so far hidden symmetry, has been unveiled. These hybrid nano systems have the potential to be used as building blocks of the future superconducting electronics devices. As also revealed in the letter, they can be tuned to serve as superconducting diodes or even transistors. Therefore, this work paves the way for advanced quantum computing components.

A key finding of the work is that there is a special kind of symmetry that allows to map any system with arbitrary number of leads to its equivalent with just two superconducting electrodes. This mapping is exact! It is provided by an analytical relation named geometric factor which allows a complete understanding of the behavior of a complicated system based on calculations of a much simpler one. That way the geometric factor allows us to investigate systems which were inaccessible to precise methods before.

The implications of these findings are vast. The study offers a new lens through which the quantum behavior of complex junctions can be understood, predicted, and manipulated. This could lead to more robust and versatile quantum devices, significantly impacting the fields of computational science and information technology.

For detailed insights, refer to the article published in Physical Review Letters.

Original publication:

Hidden Symmetry in Interacting-Quantum-Dot-Based Multiterminal Josephson Junctions
P. Zalom, M. Žonda, and T. Novotný, Phys. Rev. Lett. 132, 126505 (2024)

Further reading:

Quantum dot attached to superconducting leads: Relation between symmetric and asymmetric coupling
A. Kadlecová, M. Žonda, and T. Novotný, Phys. Rev. B 95, 195114 (2017)

The research was financed by Czech Science Foundation
project: Superconducting nanohybrids out of equilibrium, 23-