Heating Anomaly of Cold Interfacial Water under Irradiation of Mid-infrared Pulses

The mid-infrared heating of interfacial water with different initial temperatures is studied using non-equilibrium molecular dynamics simulation. It is found that under the irradiation of a pulse at 3360-3380 $cm^{-1}$ the two-dimensional water monolayer on a hydrophilic surface at a lower initial temperature acquires a much larger temperature jump. The mechanism beneath this counterintuitive phenomenon is the enhanced transition efficiency of the asymmetric OH stretching vibration due to the specific oriented configuration of water molecules at lower initial temperatures. The understanding of the anomalous phenomenon clarifies the sensitivity of the interfacial properties of water molecules to the temperature.