Advances in Quantum Control - Techniques, Applications, and Challenges

The workshop Advances in Quantum Control: Techniques, Applications, and Challenges (AQuTe25) explored the state of the art in controlling complex quantum systems. The transverse nature of control as a research field meant that participants were introduced to a broader range of topics compared to the more focussed meeting that they are accustomed to. The workshop demonstrated the importance of the field, highlighting that coherent control underpins many of the recent breakthroughs in quantum simulation, computing, sensing, and communication. The full spectrum of control approaches were represented, including quantum optimal control, feedback control, Floquet control, and shortcuts-to-adiabaticity. These control techniques were showcased in current areas of high interest, in particular, quantum computing, quantum thermodynamics, and quantum metrology. A core aspiration of AQuTe25, and one in which it was highly successful, was to bring together researchers from these various sub-communities to share the benefits and limitations of control techniques and to explore potential synergies. In this regard the choice of social activity, a hiking tour in Saxon Switzerland, was highly beneficial. It was noted by participants who had attended previous MPI workshops that this choice facilitated interactions better than other potential options (e.g. museum / castle visits).  

AQuTe25 was spread over five days and involved a total of 34 speakers (fourteen 40 minute invited talks and twenty 25 minute contributed talks). In order to stimulate interactions, the workshop was organised to ensure an almost equal balance between structured sessions and open discussion time. The various control techniques were introduced across several talks, with their mathematical properties and practical implementations extensively discussed. Commonalities across the sub-communities emerged, for example the need for careful robustness analyses and the use of control and controllability to guide the development of novel quantum devices. During his talk demonstrating the capabilities of quantum simulation in BECs via coherent control, Prof. Guéry-Odelin took a moment to show the crowd the fun-side of coherent control. He presented a gift to the workshop by spelling out AQUTE25 using matter wave diffraction orders designed by optimal control. Each session involved lively discussions which were stimulated by questions from the participants. Two late night (7pm-9pm) poster sessions, involving a total of 46 posters, allowed those participants not presenting a talk to discuss their work. Prof. Sophia Economou delivered the AQuTe25 colloquium "Quantum algorithms and quantum control". This was a particularly excellent session on the first day of the workshop, providing an introduction to one of the key areas in which quantum control is having a major impact and establishing the potential benefits of hybridised control techniques to enhance the efficacy of quantum computing architectures. Overall, the workshop atmosphere was marked by a curiosity to better understand the adjacent subfields, which made the environment very open and collegial. 

AQuTe25 in numbers: The workshop hosted 84 participants (consisting of 2 organisers, 14 invited speakers, and 78 attendees and an approximately 80-20 M-F gender split). Geographically, the composition was approximately 25% from Germany, 50% from the rest of Europe (including associated states), 15% from USA, and the remaining 10% from the RoW. Regarding the career stage, there was an equal balance between senior, mid-career, and early career researchers.