Emergence and control of complex behaviors in driven systems of interacting qubits with dissipation

A V Andreev,A G Balanov,W Li,A M Zagoskin,T M Fromhold,V V Makarov,M T Greenaway,A E Hramov

doi:10.1038/s41534-020-00339-1

Abstract

Progress in the creation of large-scale, artificial quantum coherent structures demands the investigation of their nonequilibrium dynamics when strong interactions, even between remote parts, are non-perturbative. Analysis of multiparticle quantum correlations in a large system in the presence of decoherence and external driving is especially topical. Still, the scaling behavior of dynamics and related emergent phenomena are not yet well understood. We investigate how the dynamics of a driven system of several quantum elements (e.g., qubits or Rydberg atoms) changes with increasing number of elements. Surprisingly, a two-element system exhibits chaotic behaviors. For larger system sizes, a highly stochastic, far from equilibrium, hyperchaotic regime emerges. Its complexity systematically scales with the size of the system, proportionally to the number of elements. Finally, we demonstrate that these chaotic dynamics can be efficiently controlled by a periodic driving field. The insights provided by our results indicate the possibility of a reduced description for the behavior of a large quantum system in terms of the transitions between its qualitatively different dynamical regimes. These transitions are controlled by a relatively small number of parameters, which may prove useful in the design, characterization, and control of large artificial quantum structures.

Highlights

Recent progress in experimental techniques for the fabrication, control and measurement of quantum coherent systems has allowed the routine creation of moderate-to-large arrays of controllable quantum units expected to have revolutionary applications, e.g., in sensing, quantum communication and quantum computing[1,2,3,4]
It is known that large systems comprising many functional elements tend to demonstrate emergent phenomena in their dynamics, which cannot be observed in smaller systems[19,20]
One important open question to be tackled is how the dynamics scales with the increase of the system size and what role in its change is played by emergent phenomena

Summary

Introduction

Recent progress in experimental techniques for the fabrication, control and measurement of quantum coherent systems has allowed the routine creation of moderate-to-large arrays of controllable quantum units (e.g., superconducting qubits, trapped atoms and ions) expected to have revolutionary applications, e.g., in sensing, quantum communication and quantum computing[1,2,3,4] They allow the investigation of fundamental physics, such as the measurement problem[5,6,7], the link between the chaotic behavior in classical systems and the corresponding dynamics in their quantum counterparts[8,9,10,11,12] and the relative roles of entanglement and thermalization[13,14,15,16,17]. One important open question to be tackled is how the dynamics scales with the increase of the system size (e.g., number of qubits) and what role in its change is played by emergent phenomena

Methods

Results

Conclusion