Size dependence of the changeover from geometric to magnetic confinement in ${\mathrm{In}}_{0.53}$${\mathrm{Ga}}_{0.47}$As/InP quantum wires

Photoluminescence studies on deep-etched ${\mathrm{In}}_{0.53}$${\mathrm{Ga}}_{0.47}$As/InP quantum wires of several lateral widths ${\mathit{L}}_{\mathit{x}}$≥25 nm have been performed in magnetic fields up to B=8.0 T. By optically generating a dense electron-hole plasma in the quantum wires, emission from different lateral subbands has been observed. With the magnetic field aligned along the growth direction, a changeover of the characteristic length scale that determines the carrier quantization energies from the lateral wire width to the cyclotron length is observed with increasing B. This transformation is observed when the cyclotron energy becomes comparable to the quantization energy. The magnetic field at which this transition occurs increases proportionally to the inverse of the square of the wire width in agreement with theoretical calculations. © 1996 The American Physical Society.