Quantum dots and quantum devices in 2d-semiconductors

The atomically-thin semiconductor family of transition metal dichalcogenides (2d-TMDs) offer technological advantages as platforms for quantum devices. Lack of dangling bonds, atomically-precise interfaces, absence of nuclear spins and ease of integration to form 2d heterostructures are some. I will present how we deterministically create quantum dots (QDs) in 2d-TMDs, in large-scale arrays. The QDs are single-photon sources, and exhibit better stability than their random counterparts. They are formed by stamping the monolayer flakes onto silica substrates patterned with nanopillars, over which the flake tents. I will report on the method and on the magneto-optical characterization of the emitters. The QDs can be embedded within 2d-heterostructures to form functional quantum devices: we use 1L-WSe₂ and WS₂, along with graphene and hexagonal boron nitride, to create quantum light-emitting diodes that produce electrically driven single-photons. Finally, I will introduce our current work: achieving charge-tunability of the WSe₂-QDs using field-effect type 2d-devices. We are able to controllably charge the QDs with single-electrons and single-holes - first step towards the use of spin and valley pseudospin of single carriers as optically addressable matter qubits in 2d materials.