Quantum optimal control via gradient ascent in function space and the time-bandwidth quantum speed limit

Understand

A gradient ascent method for optimal quantum control synthesis is presented that employs a gradient derived with respect to the coefficients of a functional basis expansion of the control.

• Restricting the space of allowable controls to weighted sums of the Slepian sequences efficiently parameterizes the control in terms of bandwidth, resolution and pulse duration.
• A bound showing minimum time evolutions scaling with the inverse of the control bandwidth [S.
• Lloyd and S.