Quantum-classical transition for an analog of the double-slit experiment in complex collisions: Dynamical decoherence in quantum many-body systems

We study coherent superpositions of clockwise and anticlockwise rotating intermediate complexes with overlapping resonances formed in bimolecular chemical reactions. Disintegration of such complexes represents an analog of a famous double-slit experiment. The time for disappearance of the interference fringes is estimated from heuristic arguments related to fingerprints of chaotic dynamics of a classical counterpart of the coherently rotating complex. Validity of this estimate is confirmed numerically for the $\mathrm{H}+{\mathrm{D}}_2$ chemical reaction. Thus we demonstrate the quantum-classical transition in temporal behavior of highly excited quantum many-body systems in the absence of external noise and coupling to an environment.

Figure 1

(Color online) Time power spectra related to the $\mathrm{H}+{\mathrm{D}}_2(v_i=0,j_i=0)\to \mathrm{H}\mathrm{D}(v_f=3,j_f=0)+\mathrm{D}$ schemical reaction for different moments of time. Solid lines correspond to $d=2$ and $\beta =0.003\mathrm{eV}$, dashed lines $d=5$ and $\beta =0.003\mathrm{eV}$, and dashed-dotted lines $d=10$ and $\beta =0.003\mathrm{eV}$.

Figure 2

(Color online) Classical limits for the time power spectra presented in Fig. 1 (see text).