2024/02/16 by Yuanlong Wang, Wang, Yuanlong, Gerardo A. Paz-Silva +1 · 1 citation
Physics and Astronomy · #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.2402.10438
Characterizing noise is key to the optimal control of the quantum system it affects. Using a single-qubit probe and appropriate sequences of π and non-π pulses, we show how one can characterize the noise a quantum bath generates across a wide range of frequencies -- including frequencies below the limit set by the probe's \mathbbT2 time. To do so we leverage an exact expression for the dynamics of the probe in the presence of non-π pulses, and a general inequality between the symmetric (classical) and anti-symmetric (quantum) components of the noise spectrum generated by a Gaussian bath. Simulation demonstrates the effectiveness of our method.