Realization of a two-channel Kondo model with Josephson junction networks

TL;DR

This paper demonstrates how a Josephson junction rhombi chain can be mapped onto a quantum Ising model and how a Y-shaped network of such chains can realize the two-channel Kondo effect, enabling experimental probing via Josephson current measurements.

Contribution

It introduces a novel superconducting network design that realizes the two-channel Kondo model using Josephson junction rhombi chains.

Findings

Mapping of Josephson rhombi chain to quantum Ising model

Proposal of Y-shaped network as a two-channel Kondo device

Detection of Kondo effect through Josephson current measurements

Abstract

We show that- in the quantum regime- a Josephson junction rhombi chain (i.e. a Josephson junction chain made by rhombi formed by joining 4 Josephson junctions) may be effectively mapped onto a quantum Hamiltonian describing Ising spins in a transverse magnetic field with open boundary conditions. Then, we elucidate how a Y-shaped network fabricated with 3 Josephson Junction Rhombi chains may be used as a quantum device realizing the two channel Kondo model recently proposed by Tsvelik. We point out that the emergence of a 2 channel Kondo effect in this superconducting network may be probed through the measurement of a pertinent Josephson current.