Layer-depopulation- and magnetic-field-induced resistance oscillations in a triple-layer electron system

The resistance R of a coupled, triple-layer electron system exhibits two distinct types of oscillations as a function of front-gate bias ${\mathit{V}}_{\mathrm{FG}}$ or in-plane magnetic field ${\mathit{B}}_{\mathrm{\parallel }}$. We observe up to three oscillations in R as a function of ${\mathit{B}}_{\mathrm{\parallel }}$; these correspond to the passage of the Fermi level through the partial energy gaps arising from the level anticrossings at the intersections of the dispersion curves of the three electron layers. By fixing ${\mathit{B}}_{\mathrm{\parallel }}$ and decreasing ${\mathit{V}}_{\mathrm{FG}}$, we observe additional oscillations in R as the system makes triple-to-double and double-to-single layer transitions.