Chiral Quantum Network with Giant Atoms

TL;DR

This paper proposes a novel, chip-integrable method for creating chiral quantum networks using giant atoms in superconducting circuits, enabling tunable, high-fidelity quantum information transfer without bulky magnetic components.

Contribution

It introduces a new approach to realize chiral quantum networks via giant atom effects with modulated coupling points, avoiding traditional ferrite circulators.

Findings

Achieves near-perfect chiral emission with a factor approaching 1.

Enables tunable emission direction and rate through modulation.

Demonstrates high-fidelity state transfer between remote giant atoms.

Abstract

In superconducting quantum circuits (SQCs), chiral routing quantum information is often realized with the ferrite circulators, which are usually bulky, lossy and require strong magnetic fields. To overcome those problems, we propose a novel method to realize chiral quantum networks by exploiting giant atom effects in SQC platforms. By assuming each coupling point being modulated with time, the interaction becomes momentum-dependent, and giant atoms will chirally emit photons due to interference effects. The chiral factor can approach 1, and both the emission direction and rate can be freely tuned by the modulating signals. We demonstrate that a high-fidelity state transfer between remote giant atoms can be realized. Our proposal can be integrated on the superconducting chip easily, and has the potential to work as a tunable toolbox for quantum information processing in future chiral quantum networks.