Collective quantum phenomena in dissipative systems – towards time-crystal applications in sensing and metrology

Quantum technology carries the promise to revolutionise data processing, communication, and metrology.

The current approach towards unlocking this potential builds on scalable and fully coherent devices with high technological complexity.This project follows a novel route and seeks to identify and realise quantum resources by exploiting collective phenomena in open quantum systems.

This approach does not rely on perfect coherence, instead exploits the competition between coherent interactions and dissipative processes, which yields a certain degree of robustness against external perturbations.

A prominent example are dissipative time-crystals, which constitute a many-body phase that displays persistent temporal oscillations although their evolution is heavily influenced by incoherent processes.The goal of this project is to identify and characterise such many-body phases and to perform experiments that demonstrate their applicability for sensing and timekeeping.

Our focus will be on spin-boson models which constitute simple, yet broadly relevant many-body quantum systems. Within our consortium we will implement such a system using crystals of trapped ions with in-situ cooling.

This platform allows us to address important questions, ranging from formulation of open quantum many-body dynamics under periodic driving to the use of feedback for controlling dissipative dynamics.