title: Scalable design of tailored soft pulses for coherent control.
abstract: We present a scalable scheme to design optimized soft pulses and pulse sequences for coherent control of interacting quantum many-body systems. The scheme is based on the cluster expansion and the time-dependent perturbation theory implemented numerically. This approach offers a dramatic advantage in numerical efficiency, and it is also more convenient than the commonly used Magnus expansion, especially when dealing with higher-order terms. We illustrate the scheme by designing 2nd-order self-refocusing pi pulses and a 6th-order 8-pulse refocusing sequence for a chain of qubits with nearest-neighbor couplings. We also discuss the performance of soft-pulse refocusing sequences in suppressing decoherence due to low-frequency environment.
authors.affiliation: Department of Physics, University of California, Riverside, CA 92521, USA.
authors.forename: Pinaki
authors.initials: P
authors.lastname: Sengupta
authors.forename: Leonid P
authors.initials: LP
authors.lastname: Pryadko