Full tunability and quantum coherent dynamics of a driven multilevel system

TL;DR

This paper demonstrates how Floquet engineering with longitudinal driving enhances the tunability and control of multilevel quantum systems, enabling noise-resistant quantum gates and revealing rich driven dynamics.

Contribution

It introduces a general effective model for driven multilevel systems, showing how to achieve high tunability and control without additional device complexity.

Findings

Enhanced tunability via longitudinal driving

Observation of phenomena like resonance modulation and dark states

Proposal of noise-resistant quantum gates

Abstract

Tunability of an artificial quantum system is crucial to its capability to process quantum information. However, tunability usually poses significant demand on the design and fabrication of a device. In this work, we demonstrate that Floquet engineering based on longitudinal driving provides distinct possibilities in enhancing the tunability of a quantum system without needing additional resources. In particular, we study a multilevel model based on gate-defined double quantum dots, where coherent interference occurs when the system is driven longitudinally. We develop an effective model to describe the driven dynamics of this multilevel system, and show that it is highly tunable via the driving field. We then illustrate the versatility and rich physics of a driven multilevel system by exploring phenomena such as driving modulation of resonances, adiabatic state transfer, and dark state. In the context of qubit control, we propose noise-resistant quantum gates based on adiabatic passage. The theoretical consideration we present here is rather general, and is in principle valid for other multilevel quantum systems.