Optimal control of open quantum systems

Optimal control theory (OCT) is a versatile tool that can be used to identify control strategies in the presence of decoherence, either avoiding or exploiting the environment. In this talk, I will discuss an example for each. First, for qubits encoded in the infinite-dimensional Hilbert space of bosonic modes, I will show how to employ OCT to systematically enhance performance in the implementation of strong and on-demand interactions between the qubits [1]. Second, I will discuss OCT in driven dissipative evolutions. For example, in trapped ion qubits, a protocol derived with OCT allows for the resource-efficient dissipative generation of an entangled state [2]. Finally, I will assess prospects for quantum control in reservoir engineering where the desired dissipation can be realized via quantum non-demolition measurements.

[1] D. Basilewitsch, Y. Zhang, S.M. Girvin, C.P. Koch, arXiv:2111.15573

[2] D.C. Cole, S.D. Erickson, G. Zarantonello, K.P. Horn, P.-Y. Hou, J.J.

Wu, D.H. Slichter, F. Reiter, C.P. Koch, D. Leibfried, arXiv:2108.03136