Application of optimal control to improve shaking protocols for quantum accelerometers

With the design and construction of fault-tolerant quantum computers still a number of years away, a more near-time application of quantum technology may lie in the field of quantum sensing. Here the interaction of quantum systems with their environment is used to extract information about the environment's properties – for instance the strength of a magnetic field or its acceleration with respect to a reference frame. Shaken lattice is an example to realize a quantum sensor to detect the latter: A cloud of cold atoms is trapped in a configurable optical lattice and manipulated by moving ("shaking") the lattice. The final momentum distribution of the atoms yields information about the presence of external accelerating forces on the atoms, where the sensitivity is dependent on the shaking control. With the goal to design high-precision sensors in mind, this inevitably motivates the application of quantum optimal control techniques to find shaking protocols that improve the system's sensitivity. In this talk we discuss the common approach derived from Mach-Zehnder interferometry and present two optimal control strategies to push the sensitivity.