Photoluminescence measurements in Be-δ-doped back-gated quantum well

We measured the photoluminescence (PL) spectra of a two-dimensional electron system induced in a Be-δ-doped GaAs/AlGaAs quantum well (QW) with a back gate. The electron density is controlled by means of the back-gate voltage. We estimated the electron density using the magneto-optical method and the PL linewidth, and also by undertaking transport measurements. We show that a uniform 2DES as large as 1 mm2 is induced by the back-gate operation from 2.5 × 1010 cm−2. This experiment indicates that optical measurement with a back-gated QW is advantageous for studying the low-density 2DES.