Rapid measurement of quantum systems using feedback control.
We introduce a feedback control algorithm that increases the speed at which a measurement extracts information about a d-dimensional system by a factor that scales as d(2). Generalizing this algorithm, we apply it to a register of n qubits and show an improvement of O(n). We derive analytical bounds on the benefit provided by the feedback and perform simulations that confirm that this speedup is achieved.
Combes
Joshua
J
Centre for Quantum Computer Technology, Centre for Quantum Dynamics, Griffith University, Nathan 4111, Australia.
Wiseman
Howard M
HM
Jacobs
Kurt
K