Spatial Addressing of Qubits in a Dispersive Waveguide

TL;DR

This paper demonstrates a novel method for spatially addressing superconducting qubits within a waveguide by leveraging dispersion effects, enabling rapid quantum control through position-dependent interactions.

Contribution

It introduces a new approach using dispersion and self-focusing to achieve spatial addressing of qubits separated by sub-wavelength distances.

Findings

Dispersion enables spatial control of qubits in a waveguide.

Self-focusing effect creates position-dependent qubit interactions.

The method allows rapid quantum state manipulation.

Abstract

Waveguide quantum electrodynamics, the study of atomic systems interacting with propagating electromagnetic fields, is a powerful platform for understanding the complex interplay between light and matter. Qubit control is an indispensable tool in this field, and most experiments have so far focused on narrowband electromagnetic waves that interact with qubits at specific frequencies. This interaction, however, changes significantly with fast, broadband pulses, as waveguide properties like dispersion affect the pulse evolution and its impact on the qubit. Here, we use dispersion to achieve spatial addressing of superconducting qubits separated by a sub-wavelength distance within a microwave waveguide. This novel approach relies on a self-focusing effect to create a position-dependent interaction between the pulse and the qubits. This experiment emphasizes the importance of dispersion in the design and analysis of quantum experiments, and offers new avenues for the rapid control of quantum states.