Speaker
Description
Exotic states of matter are predicted to be found in 2D bilayer systems such as InAs/GaSb heterostructures. These are usually described as two adjacent quantum wells of InAs and GaSb where the conduction band of the former lies below the valence band of the latter. We present a variation of this structure using an insulating AlSb barrier between InAs and GaSb layers, acting as an n and a p layer, respectively. We highlight the observation of a two-dimensional electron gas (2DEG) and a two-dimensional hole gas (2DHG) created in the vicinity of the insulating AlSb barrier. Using capacitance techniques, we succeed to measure the accumulation of charge carriers close to the barrier already in equilibrium regime, i.e., without any applied DC voltages. By applying positive DC bias, we modify the density of the 2D charge gas as can be seen via the Shubnikov-deHaas (SdH) oscillations. This scenario is motivating for deeper understanding about how excitons are generated and behave in an Excitonic condensate or Bose-Einstein condensate (BCS) regime. Further interaction effects that are created from this observation will be discussed.
