# Tunable quantum switcher and router of cold atom matter waves using artificial magnetic fields

## TL;DR

This paper demonstrates a tunable quantum switch and router for cold atom matter waves using artificial magnetic fields in a minimal two-rung ladder system, enabling control over atom transport and routing.

## Contribution

It introduces a novel method to control atom transport and routing in a minimal two-rung ladder with artificial magnetic flux, with potential applications in quantum device interfaces.

## Key findings

- Atom transport can be switched from blockade to transparency by tuning system parameters.
- Atoms can be perfectly routed into different channels with wavevector modulation by magnetic flux.
- The approach can be extended to other artificial quantum systems like superconducting circuits.

## Abstract

We investigate the single-atom transport in a two-leg ladder with only two rungs, which together with the legs, enclose an artificial magnetic flux. Here, the atoms on the two legs possess opposite onsite energies that produce an energy offeset. We find that the atom incoming from the left leg can experience from blockade to tranparency via modifying the onsite energy, hopping strength, or magnetic flux, which can be potentially used for a quantum switcher. Furthermore, the atom incoming from the left leg can also be perfectly routed into the right leg, when, intriguingly, the outgoing atom in the R channel possesses a wavevector that can be modulated by the magnetic flux. The result may be potentially used for the interface that controls the communication between two individual quantum devices of cold atoms. The method can also be generalized to other artificial quantum systems, such as superconducting quantum circuit system, optomechanical system, etc.