Left axis: excited-state probability P_e(t). Right axis: QSNR, Q_gamma_phi(t)=gamma_phi^2 F_Q(t), from a finite-difference Bloch derivative.
Abstract
This demo shows a qubit driven by a fixed-width Gaussian pulse. The left curve is excited-state probability, the dashed gray line is the normalized pulse envelope, and the right-axis curve is QSNR for estimating dephasing. The two sliders control pulse amplitude and dephasing strength in units set by the fixed pulse width.
Method
We evolve a Bloch vector with
plus a dephasing map at each timestep.
For
the QFI for parameter is
and we use with finite difference
The right-axis curve is
with two trajectories at and .