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Fei Wang is the first author, printed as F. Wang, of the 2016 experimental study of robust dynamical decoupling with finite-strength control pulses. The corresponding 2017 APS abstract identifies Fei Wang and the same five coauthors under the same research title.^[ref]

The experiment controlled an electron-spin qubit at a nitrogen-vacancy center in diamond. A $532\mathrm{nm}$ laser initialized and read out the center through fluorescence; a transmission line delivered microwave control and deliberately injected noise. Comparing pulse sequences tested whether slow, finite-duration pulses could suppress dephasing and relaxation noise, rather than requiring ideal instantaneous rotations. The study found that appropriately arranged slow pulses could approach the performance of strong fast pulses.^[ref]

An original pulse-area example explains the constraint. For resonant control $H_c=\hslash \Omega {\sigma }_x/2$, a constant pulse of duration $t_p$ rotates through $\Omega t_p$. A $\pi$ pulse with $\Omega =2\pi \times 100\mathrm{kHz}$ lasts $5\mu \mathrm{s}$; at $\Omega =2\pi \times 10\mathrm{kHz}$ it lasts $50\mu \mathrm{s}$. Both have the same rotation angle, but the system experiences noise for ten times longer during the second pulse. The demonstrated sequence design addresses that finite-duration problem; pulse area alone does not establish noise cancellation.