Fig. 6: The time-dependent nonadiabatic transition amplitude when the \({{{\mathcal{PT}}}}\) Hamiltonian encircles the EP.
From: Dynamical topology of chiral and nonreciprocal state transfers in a non-Hermitian quantum system
a–d Encircling starting from the \({{{\mathcal{PT}}}}\)-symmetric regime. Clockwise and counterclockwise encircling with the initial state \(| {\alpha }_{A}(0)\left.\right\rangle\) in (a, b). Similar encircling with \(| {\beta }_{A}(0)\left.\right\rangle\) in (c, d). e–h Encircling starting from the \({{{\mathcal{PT}}}}\)-broken regime. Clockwise and counterclockwise encircling with the initial state \(| {\alpha }_{B}(0)\left.\right\rangle\) in (e, f). Similar encircling with \(| {\beta }_{B}(0)\left.\right\rangle\) in (g, h). The color maps for the time-dependent nonadiabatic transition amplitude when changing the encircling period. The cyan circles with error bars represent experimental results obtained from the raw measured data. Solid and dashed lines on the side plane correspond to the theoretical calculation from Eq. (17) and the numerical simulation from C1(t) and C2(t), where the encircling period T = 250 μs. The error bars are estimated as the standard deviation (1σ) from 5 rounds of quantum state tomography experiments.
