Heterogeneities in Quantum Materials

Seeks to establish an atomistic-level understanding of structure-property relationships in heterogeneous quantum materials to enable the design of new generations of quantum materials.

A spin-polarized four-probe scanning tunneling microscope measures spin-dependent electrical conductance on topological insulator Bi2Te2Se. By reducing the probe spacing at low temperature, most electrons are “pushed” to the topological surface states, showing a quasi-ballistic spin-polarized conductance.

The interplay of reduced dimensionality and heterogeneities in heterostructures, nanostructures, molecular compounds, and other complex systems brings materials into regimes dominated by quantum properties of defects, interfaces, and disorder. Such heterogeneous quantum materials often host exotic states that hold promise for the development of highly engineered, scalable, and functional quantum systems for applications in computation, sensing, and communication. Despite the revolutionary opportunities, significant challenges remain in tailoring structures, controlling delicate interactions, and protecting quantum states from decoherence to enable encoding and transduction for quantum information science and technology.

The overarching goal of the Heterogeneities in Quantum Materials theme is to understand the formation, behavior, and coherence of quantum states in low-dimensional quantum materials through nanoscale control over defects, interfaces, and disorder. This goal is achieved via the execution of three specific aims:

Reveal quantum states enabled by heterogeneities.
Understand quantum interactions in heterogeneous quantum systems.
Establish and enhance coherence and entanglement by controlling heterogeneities.

Our hypothesis is that nanostructured materials possess novel quantum properties that can be introduced and controlled by heterogeneities and harnessed for robust, high-performance energy and quantum information science applications. This science theme builds directly on our strengths and expertise across atomic-level measurement, control, and modeling of low-dimensional materials, via innovative development and utilization of scanning probe and electron microscopies and spectroscopies, low- frequency Raman and ultrafast laser spectroscopies, all enhanced by first-principles calculations facilitated by machine learning approaches. Once realized, our research will enable the design of new generations of quantum materials by harnessing heterogeneities to catalyze a paradigm shift of quantum information science. In the meantime, the development of unique capabilities will offer the scientific community and our users a first-principles approach to quantum materials by interrogating individual heterogeneities, understanding their interactions, and advancing them as new materials with desirable quantum functions.