Oscillations of photoconductivity and negative absolute conductivity in quantum wires

The phenomenon of oscillating photoconductivity as a function of photoinjection energy is studied by Monte Carlo simulation in quasi-one-dimensional quantum wire structures. It is demonstrated that the amplitude of the oscillations of photoconductivity may be so large that this leads to a negative absolute conductivity at injection energies that are multiples of the optical phonon energy. These oscillations are associated with inelastic optical phonon scattering, leading to an asymmetric electron distribution function established under conditions of intensive electron photoinjection to the subband bottom or close to energies that are multiples of the optical phonon energy. Simulation results suggest that quasi-one-dimensional quantum wires are ideal for the experimental observation of negative absolute conductivity at low lattice temperatures.