Answer Happy

20 U (EV) -10 1. Barrier suppression intensity of hydrogen Consider the potential of a hydrogen atom (blue 40 line) in a strong alternating electric field. We know from quantum mechanics classes that it requires 13.6 eV to ionize atomic hydrogen (green line). 0 Adding the binding potential of the atom and the 3 -20 potential at peak field strength, we arrive at the effective potential depicted by the orange line in -40 the plot on the righthand side. Here the field -5 0 5 10 strength has been chosen to suppress the barrier (A) down to -13.6 eV, and the bound electron can leave the potential without tunneling at the peak field strength. 1. Write an expression for the binding potential of a hydrogen atom. 2. Write an expression for the potential in a linear electric field. 3. Determine the position (max of the local maximum of the sum of both potentials. (roughly at +0.2 nm in the plot) 4. Which electric field is required to suppress the barrier to -13.6 eV (as shown in the plot)? 5. Convert the peak electric field Ê into intensity I (in W/cm2, effective value). 6. What optical power is needed to reach the barrier suppression with a l=1 um laser system that is focused to an area of 1 um?? (4 is the wavelength) 7. How many photons fit into a cube with dimension 2, located at the focused intensity according to 5. and 6.