In this approximation we do not consider electron-electron interaction in a crystal.

The potential due to electron-electron interactions is not periodic.

This effect is due to electron-electron interactions, which are not considered in conventional band theory.

In this case the electron-electron interaction gives rise to a significant deviation from the hydrogen potential.

The fractional quantum Hall effect is more complicated, as its existence relies fundamentally on electron-electron interactions.

As in an ideal gas, electron-electron interactions are completely neglected.

MacDonald's area of interest is on how electron-electron interactions affect electronic properties in condensed matter systems.

In this case, the role of electron-electron interaction must be considered using the many-body physics description.

In the strongly correlated electron system, it is necessary to consider the electron-electron interaction.

It was realized that the high temperature superconductors are examples of strongly correlated materials where the electron-electron interactions play an important role.