Quantum Localization in a van der Waals Metal

Speaker: Morgan Thidel

Affiliation: Harvard University

Abstract: Localizing electrons is a fundamental pursuit in physics. On one hand,
quantum information and sensing technologies require localizing a quantum system to
prevent decoherence into its environment. On the other hand, strongly correlated
phases and unconventional superconductivity can emerge from many-body localization
and flat bands. Normally, the precise control of electrons relies on the localization of
quantum states within a spectral vacuum. As such, single atoms trapped by optical
tweezers as well as defect levels trapped in the bandgap of insulating materials are two
common approaches to the design of qubits. Here, I use scanning tunneling
microscopy/spectroscopy (STM/S) to demonstrate and investigate the interference of
electronic wavefunctions in crystals as a mechanism for quantum localization. In this
talk, I will present a new approach to the quantum localization of bound states in the
continuum via hopping interference in the metallic van der Waals (vdW) material
Pd5AlI2 (1). This discovery challenges the conventional understanding that defect-bound
states used for solid-state qubit technologies require an insulating band gap, potentially
expanding materials platforms for quantum technologies to include metals with
frustrated hopping. Next, I use the same material platform to provide spectroscopic
evidence for the scaling theory of Anderson localization motivating the application of
vdW metals for tunable many-body localization physics (2).