Molecular beam epitaxy (MBE) is our method of choice of creating exotic single-crystal, thin film materials (insulating, metallic, semiconducting, magnetic, topological… you name it!). Using this technique, we can atomically control and engineer different material heterostructures. To accomplish such a feat, we require very pure environments to grow in, namely, our chamber base pressures are 10-11 torr (that’s 13 orders of magnitude less than atmospheric pressure!). We evaporate elemental materials onto a heated crystal substrate to create epitaxial films of choice. Since growth rates are relatively slow (angstroms per minute), we can grow successive parts of the film atomic layer by layer. Even more fascinating is that we can monitor the growth in-situ with a phenomenal technique called reflection high energy electron diffraction (RHEED). By monitoring the diffraction pattern and relative intensities from RHEED, we can observe when an atomic layer begins growing and when it finishes in real time. The combination of MBE (ultra-high vacuum, slow growth rates) and RHEED (in-situ monitoring of growth) allow our laboratory to engineer new materials at the atomic level to explore a breadth of physical interactions.
| Science | Epitaxial Growth … | Method: Molecular Beam Epitaxy