Grant: Research Tools and Instruments

Two recent developments in the area of 2-dimensional materials have exploded the materials phase space of these materials and heterostructures: 1) the discovery that many “layered” materials can be exfoliated in a manner similar to graphene, and 2) the discovery that small twist angles between layers can give rise to rich electronic phase diagrams by quenching kinetic energy of the electrons down to interaction scales. From this vast 2D materials space, there have been observations and predictions of unique optical properties, topological behavior, superconductivity and more. As the 2D nature of these materials and devices naturally integrates into our existing 2D lithographic platforms for electronic and photonic devices, there is substantial interest in both exploring the exciting physics of these materials, as well as pushing these materials forwards into applications like quantum information and sensing. Here, we request a controller upgrade for an existing low-temperature scanning probe microscope (SPM) with already integrated optical spectroscopy capabilities, in order to study the optoelectronic emission characteristics and electronic scattering properties of defects in 2D materials. This upgrade is necessary both to support the ongoing state-of-the-art work this instrument is capable of due to an aging controller system, as well as support novel integrated device-centered measurements of 2D materials. The new controller will enable greater measurement flexibility, integration of external hardware, such as the optical spectrometer used for tunneling luminescence measurements, and allow optimization of signal to noise for spatially resolved tunneling spectroscopy measurements used to determine the local density of states and quasiparticle interference measurements (QPI). These capabilities will allow us to investigate single defect quantum emitter states to elucidate the identity of the emission centers, emission processes, and interaction with bulk states. The improved QPI capabilities will also allow us to investigate interaction and topologically driven selection rules in defect scattering, probing both the fundamental physics of the electrons in these materials and connecting to bulk properties like resistance and magnetoresistance. These measurements require high stability instrumentation and integration with external measurements; the requested controller will ensure that these needs are met by upgrading the existing electronics and software to enhance the capabilities of the existing, robust base hardware representing a ~$1M asset. Our ability to identify individual defects, and probe the electronic states, structure, and sub-nm resolved optical properties, as well as control the underlying electronic states through fabrication and gating, will allow us to to explore and engineer new quantum emitters and novel electronic materials and integrate them into device platforms for future technologies.