Controlling Quantum Interferences in IR Vibrational Excitations in Metal Carbonyls

Coherent controls over vibrational excitations in metal di-carbonyls were demonstrated by using phase-shaped mid-infrared pulses. The phase of the inter-state coherence between two different normal-modes was controlled by changing the phase step of the stepwise spectral phase profile. The quantum interference between multiple vibrational excitation paths in resonant two-step excitations was manipulated by the similar spectral phase control. The results experimentally confirmed that coherent control over multiple vibrational degrees of freedom works properly in condensed phases. There remains the possibility for increasing excitation efficiency by introducing group-delays and by optimizing polarization state of the excitation pulse.