Exploring 2D Quantum and Acoustic Systems Using Scanning Probes

Abstract

The world of quantum materials is made rich by the coexistence of many, many interacting electrons, giving rise to complex and fascinating phases of matter such as topological superconductivity. Such emergent quantum phenomena are associated with small interaction energy scales, appearing only in specific materials at ultra low temperatures. In this thesis I will address two distinct pathways towards studying strongly correlated materials: 1) creating better instrumentation and 2) discovering new materials. In order to study already existing quantum materials, and more specifically topological superconductors, I will present the design and construction of a mK-base temperature scanning probe microscope. This system is the first of its kind to support simultaneous scanning tunneling microscopy and optical detection pendulum atomic force microscopy at mK temperatures. Such a combination opens the door for the realization of my proposed topologically protected quantum logic operation in the topological superconductors. An alternative approach is to discover new systems that are potential hosts for strongly interacting phenomena. Discovering new quantum systems can be laborious and expensive; however, the dispersion of electrons can accurately be mimicked by classical waves, such as sound. The ability to quickly and cheaply 3D print acoustic metamaterials allows for rapid iterations and the discovery of novel lattice geometries which can then be brought to the quantum regime. I will present the experimental measurement and simulation of macro-scale acoustic metamaterials to prototype new flat band lattices. Additionally, I will discuss the development of a novel platform for designing arbitrary dispersions of surface acoustic waves in piezoelectric crystals using metamaterials.