Fig. 31.

Development of grid-controlled quantum dots in 2D materials. a Schematic diagram of gate defining a double-layer graphene quantum dot. Graphene is suspended in electrodes. The electric field and carrier density distributions are controlled by the rear and top grid voltages V_b and V_t, while transport measurements can be made by applying a biased V_sd to the electrode [357]. b Schematic diagram of gated BLG quantum dots with adjustable polarity. Where, yellow is the split grid and green is the finger grid L, M and R. Make edge contacts (orange) at both ends of the channel [404]. c Figure shows the adjustable polarity and band diagram. Reproduced with permission [404]. Copyright (2021), American Chemical Society. d h-BN encapsulated grid-controlled MoS₂ double quantum dots. Above: Schematic diagram of the sample structure on the left, the potential distribution of COMSOL simulated MoS₂ layer on the right, and the closed contour representing the possible location of the quantum dot. Below: Band structure of MoS₂ under different gated voltages. This realizes the evolution of a two-quantum-dot system from weak coupling to strong coupling to form a large single quantum-dot. Reproduced with permission [407]. Copyright (2017), American Association for the Advancement of Science. e h-BN/InSe/h-BN heterostructure has graphene contacts and multiple top grids. Each layer structure display: 2D InSe (red), graphene (dark gray), h-BN (blue), Cr/Au contacts, top grid (yellow), Si/SiO₂ substrate (light gray). Reproduced with permission [408]. Copyright (2018), American Chemical Society