Title: One component quantum mechanics and leakage free path

Speaker: Prof. Lianao Wu, Department of Physics, the Faculty of Science and Technology, UPV-EHU in Leioa (https://www.ikerbasque.net/es/lianao-wu)

Location**:** HP 4351 (MacPhail Room)

Date: Friday, Sept 8, 2023** **

Time: 3:30 – 4:30 pm (Coffee starts at 3 pm in the adjacent board room)

**Abstract: **We use a Feshbach P-Q partitioning technique to derive a closed one- component integro-differential equation. The resultant equation properly traces the footprint of the target state in quantum control theory. The physical significance of the derived dynamical equation is illustrated by both general analysis and concrete examples. Leakage from an encoded subspace to the rest of the system space is a particularly serious problem for which leakage elimination operators (LEOs) were introduced. By using the resultant dynamical equation, we show that the effectiveness of LEOs depends on the integral of the pulse sequence in the time domain, which has been missing because of the idealization of pulse sequences. Our results are applied to a three- level system for the nitrogen-vacancy centers under an external magnetic field and are illustrated by the fidelity dynamics of LEO sequences, ranging from regular rectangular pulses, random pulses, and even disordered (noisy) pulses.

Please contact** Prof. Yiqiang Zhao** (zhao@math.carleton.ca) if you would like to set up an individual meeting with the speaker.