A High‐Mobility Hole Bilayer in a Germanium Double Quantum Well
Alberto Tosato, Beatrice Ferrari, Amir Sammak, A. R. Hamilton, Menno Veldhorst, Michele Virgilio, Giordano Scappucci
Abstract
Abstract A hole bilayer in a strained germanium double quantum well is designed, fabricated, and studied. Magnetotransport characterization of double quantum well field‐effect transistors as a function of gate voltage reveals the population of two hole channels with a high combined mobility of and a low percolation density of . The individual population of the channels from the interference patterns of the Landau fan diagram was resolved. At a density of the system is in resonance and an anti‐crossing of the first two bilayer subbands is observed and a symmetric‐antisymmetric gap of is estimated, in agreement with Schrödinger‐Poisson simulations.