Quantum-enhanced Sensing via Quantum Control

Quantum technologies aim to exploit quantum coherence and entanglement, the two essential elements of quantum physics. Successful implementation of quantum technologies faces the challenge to preserve the relevant nonclassical features at the level of device operation. It is thus deeply linked to the ability to control open quantum systems. The currently closest to market quantum technologies are quantum communication and quantum sensing. The latter holds the promise of reaching unprecedented sensitivity, with the potential to revolutionize medical imaging or structure determination in biology or the controlled construction of novel quantum materials. Quantum control manipulates dynamical processes at the atomic or molecular scale by means of specially tailored external electromagnetic fields. The purpose of QuSCo is to demonstrate the enabling capability of quantum control for quantum sensing and quantum measurement, advancing this field by systematic use of quantum control methods. QuSCo will establish quantum control as a vital part for progress in quantum technologies. QuSCo will expose its students, at the same time, to fundamental questions of quantum mechanics and practical issues of specific applications. Albeit challenging, this reflects our view of the best possible training that the field of quantum technologies can offer. Training in scientific skills is based on the demonstrated tradition of excellence in research of the consortium. It will be complemented by training in communication and commercialization. The latter builds on strong industry participation whereas the former existing expertise on visualization and gamification and combines it with more traditional means of outreach to realize target audience specific public engagement strategies.


work package 1

Foundations of quantum optimal control for quantum sensing and measurements

Start Month 1 – End Month 48
Lead Beneficiary: INRIA

The aim of WP1 is to establishing mathematical foundations of optimal control of open quantum systems with and without measurement. We will investigate accessibility and (approximate) controllability to explore the limits of control of open quantum systems. We will attack this problems both using techniques coming from mathematical analysis and from algebra. Also we will develop new numerical optimal control techniques tailored to disruptive and non-disruptive measurements and we will explore the limits of control under dissipation as well as reservoir engineering. We will then  adapt these theoretical tools to the different experimental platforms of QuSCo.

TASK 1: New developments in the control of open quantum systems?

TASK 2: New developments for a system theoretical description of controllability

TASK 3: New developments for numerical optimal control

work package 2

Quantum sensing of classical signals

Start Month 1 – End Month 48
Lead Beneficiary: CEA

This WP deals with the measurement of classical signals by single or ensembles of quantum systems. The goal here is to use at its maximum potential the quantum nature of the sensor by applying elaborate quantum optimal control schemes as well as quantum state engineering to enhance its sensitivity. We will achieve this in 3 different types of sensors : NV centers in diamond (magnetic field sensing), neutral atoms (magnetic and electric field sensing), and dopants in silicon (magnetic resonance spectroscopy)

TASK 1: Optimal control for quantum sensing

TASK 2: Quantum state engineering for quantum sensing

work package 3

Quantum sensing of quantum signals and quantum measurements

Start Month 1 – End Month 48
Lead Beneficiary: TU-Wien

This WP focuses on situations where one needs to control and/or read out quantum properties of complex many body quantum systems. The main objectives are to
(i) develop quantum-limited measurement tools for large complex quantum systems and minimize / fully control the quantum back action;
(ii) develop tools for optimized control of quantum properties of complex quantum systems and steering quantum many quantum body dynamics from the measurements;
(iii) closed-loop control complex many body quantum systems. Typical applications will be in setting, controlling and reading quantum computation, quantum communication, and quantum simulation, as well as investigating fundamental questions about many body quantum systems in general.  Systems studied are: complex multi-qubit circuit QED systems and ultra-cold atom quantum many body systems.

TASK 1: Tailor measurements in a complex multi-qubit quantum processor

TASK 2: What can one infer from measurements on large cold atom based many body quantum systems?

TASK 3: Repeated quantum-limited measurement of many body systems and study its quantum feedback onto the system

TASK 4: Combine the above and establish control of quantum many body systems