Using the model of the scanning tunneling microscope that we discussed in class energy (6) vacuum tunneling electron 6r (sample) bias voltage (eV) - ɛs- eV TG (tip) sample tip (a) Using a simple potential barrier approximation, what would be the probability of an electron tunneling through to the probe if the material is copper (work function = 4.4 eV) and the probe is .5 nm from the surface? Assume the energy of the particle is 7 eV (the Fermi energy of copper) and that the potential barrier is 4.4 eV above that. (b) Assuming the current is proportional to the tunneling probability, by what factor would the current increase if you moved the probe .1 nm closer to the surface?

Using the model of the scanning tunneling microscope that we discussed in class energy (6) vacuum tunneling electron 6r (sample) bias voltage (eV) - ɛs- eV TG (tip) sample tip (a) Using a simple potential barrier approximation, what would be the probability of an electron tunneling through to the probe if the material is copper (work function = 4.4 eV) and the probe is .5 nm from the surface? Assume the energy of the particle is 7 eV (the Fermi energy of copper) and that the potential barrier is 4.4 eV above that. (b) Assuming the current is proportional to the tunneling probability, by what factor would the current increase if you moved the probe .1 nm closer to the surface?