Quantum resonance, Anderson localization, and selective manipulations in molecular mixtures by ultrashort laser pulses

Abstract

We show that the current laser technology used for field-free molecular alignment via impulsive Raman rotational excitation allows for observing long-discussed nonlinear quantum phenomena in the dynamics of the periodically kicked rotor. This includes the scaling of the absorbed energy near the conditions of quantum resonance and Anderson-like localization in the angular momentum. Based on this, we show that periodic trains of short laser pulses provide an efficient tool for selective rotational excitation and alignment in a molecular mixture. We demonstrate the efficiency of this approach by applying it to a mixture of two nitrogen isotopologues (${}^{14}$N${}_{2}$ and ${}^{15}$N${}_{2}$), and show that strong selectivity is possible even at room temperature.