Electronic Materials

Processing and storing information already constitutes a significant fraction of the global energy demand, which will soon become unsustainable. Neuromorphic computing holds a promise to address this problem by operating similarly to the human brain, which is over 1 million times more energy efficient than modern computers. Unfortunately, efficiently recreating the complex dynamics of neurons and synapses with inorganic materials is quite difficult.

Biological signals can be mimicked by quantum phase transitions, which carry an inherently low energy burden. One example, charge density waves (CDWs), arise from electron—phonon interactions and have been utilized to mimic both synaptic and neuronal functionalities. However, simultaneously achieving both useful operation temperatures and large signal is difficult.

Our group seeks to use quasi 2-dimensional superlattice materials to tune these transitions, since they are known to increase both the transition temperate and amplitude of CDW signals. A promising material for this is tantalum disulfide due to its 2D nature and rich CDW behavior. Starting from scratch we built a new synthesis platform for sulfide superlattices, which are now being evaluated for simulation of neuronal dynamics.

Quantum computers hold potential to solve scientific and energy related problems intractable for classical hardware and algorithms. One promising avenue for quantum computers uses superconducting circuits to act as artificial atoms. Limiting such approaches are materials defects in the constituent circuit elements which consist of various superconductor, insulator, and interfacial layers. These defects break quantum coherence, which causes quantum computations to be lost before they can be read-out.

Our group is working on low defect density materials platforms for superconducting quantum circuits. Based on rocksalt nitrides, we have identified a unique suite of materials such that each element is inherently low-loss, chemically compatible, and structurally commensurate. We are working to understand the underlying materials defects that lead to decoherence as well as build epitaxial superconducting quantum circuits from them.