OPTIMAL-CONTROL OF QUANTUM-SYSTEMS ON METALLIC SURFACES

Optimal control of quantum processes on a metallic surface is studied. The subject of this control are transitions between states of the quantum system. The objective of optimization is to squeeze the ground-state wavefunction with help of the higher electronic level. The quantum system is modelled within the Born-Oppenheimer approximation with effective potentials of displaced harmonic oscillators. The mean's of control is a time-dependent pulsed electric field. Pulse durations considered were about as long as a vibrational period but the envelope of the pulse could vary on a shorter time scale. Metallic reflection was treated within the so-called hydrodynamic approximation. Results show that within the hydrodynamic approximation and far from the plasma frequency the optimal field on the surface has a very similar shape to, but with different amplitude than, the optimal field of the vacuum.