Super-abiabatic control of complex quantum systems

Presented by Aurélia Chenu, University of Luxembourg

Controlling the dynamics of quantum systems with high-fidelity is becoming a necessity to advance quantum science and technology. Techniques known as shortcuts to adiabaticity (STA) tailor excitations in nonadiabatic processes to prepare a given state in a finite time, without the requirement of slow driving. Their developments in isolated quantum systems have found broad applications. I will first present an experimental demonstration of STA in the control of compression and expansion of a Fermi gas, which results into friction-free strokes that can be implemented to increase the power output of a heat machine while maintaining a high efficiency.

STA are however severely limited to isolated systems. Extending such control techniques to open systems is highly desirable in view of applications to cooling, and more generally, in finite-time thermodynamics. I will present a universal scheme for the control of open systems, defining a trajectory-based equation of motion that allows for the control of any arbitrary dynamics. Its application will be given for controlling the temperature and squeezing of a single-particle thermal state in a harmonic trap.