A pr 1 99 5 Charge density oscillations in a quasi - two - dimensional electron gas for integer filling factors

The possibility of charge density oscillations in a finite-thickness two-dimensional system is investigated for strong magnetic fields and integer filling factors. Using an effective action formalism, it is shown that an oscillatory charge density (OCD) is generated in a self-consistent way and is favored energetically over homogeneous distributions. It is smooth on the scale of the sample thickness and of the magnetic length. The modulus of its wave vector is shown to be experimentally accessible. The Hall voltage and the current density are shown to oscillate with the same wave vector when a weak current is applied. The stability of the charge oscillations against impurity potentials is discussed.