NTE0113

Ballistic electronics

• requires a system size smaller than spinrelaxation length.
• is described by the Drude model.
• do not require phase coherent conductor.
• case magnetic field generate Aharonov-Bohm phase.

Could we manipulate individual atoms today?

• yes
• no

In Auger electron spectroscopy peak shapes give information about

• the layer thickness
• the pressure in the analytical chamber
• chemical binding states

Choose the right process sequence of "lift-off" lithography! Surface cleaning -

• metal deposition - resist coating - development - resist removal
• metal deposition - resist coating - metal etching - development
• resist coating - development - metal deposition - resist removal
• resist coating - metal deposition - resist removal

In the Drude model

• electrons move with a drift velocity due to backscattering.
• electrons scatter on the atoms of the lattice.
• the wire length should be smaller than L_e.
• the current voltage relation deviates from Ohm's law.

With scanning tunneling microscope…

• individual atoms can be visualized and manipulated.
• biological systems can be widely studied.
• individual atoms can not be manipulate.
• surface can be studied since 1970s.

A molecule having N atoms

• has 3N-3-3 vibrational modes.
• has N silent modes.
• always has 3 rotational modes.
• has no vibration modes if N<3.

Microfluidics

• operates at the large Raynolds number limit.
• systems show laminar flow.
• : mixing of liquids is difficult due to presence of turbulances.
• channels are costy which limits the use of lab on chip devices.

In a SEM the diffraction limit is much shorther than for optical microscope, due to

• high speed of electrons
• small electron mass
• particle like nature of electron
• large depth of field.

The dielectric function

• cannot be negative
• always real
• a linear function of the charge susceptibility
• constrained in to the [0,1] interval.