DMREF: Collaborative Research: Accelerated discovery of chalcogenides for enhanced functionality in magnetotransport, multiorbital superconductivity, and topological applications

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

NON-TECHNICAL DESCRIPTION: Over the past decades, the discovery, understanding and applications of new solid-state materials have played a crucial role in modern technology. However, devices based on silicon have hit a bottleneck in terms of the amount of information that can be packed in nano-dimensions and still avoid the complications due to heating. This project will develop new paradigms, new principles and new classes of materials to design the next generation of multifunctional devices. The materials will be drawn from the heavy transition metal dichalcogenides (TMDCs) that combine topology and magnetism together to yield unusual magneto-transport properties. There is the potential to develop topological field effect transistors and thermomagnetic spintronic devices. The specific goals of this project are to synthesize TMDCs in bulk and thin film form, to explore their electronic properties, and compare with theoretical calculations. A tight-knit feedback loop where theory guides experiments and experiments inform theory will allow the team to design materials with the desired functionality. The projects will have multiple impacts on a broader scale through (i) synthesis of new materials that can be dispersed to the condensed matter community; (ii) creation and dissemination of modeling tools, algorithms, and software for computer-aided materials design; (iii) generation of web-based access and dissemination of materials-specific data toward enhancement of infrastructure for materials research; (iv) creation of a new online course and comprehensive training of graduate and undergraduate students across the breadth of topics (chemistry of materials, complementary spectroscopies, and multi-scale theoretical modeling; (v) coordination with local museums and schools to bring the excitement of new quantum materials to the public and the next generation of scientists; and (vi) and a new face to physics with three women in leadership positions in this team. TECHNICAL DESCRIPTION: The comparable energy scales of spin-orbit coupling and Coulomb correlations and the multi-pronged tunability by chemistry, electric field and strain afforded by van-der-Waals coupled layered structures of TMDCs, opens up an entirely new and rich parameter regime not available previously. The goal of this project is to explore TMDCs through a combination of synthesis, characterization and theoretical modeling and to determine a pathway for predicting and controlling the magneto-transport properties of these materials. The project team consists of PIs with complementary skills. The team is synergistic with expertise in material synthesis in bulk and thin film form, ability to perform spectroscopy in real-and momentum space, and advanced theoretical and computational methods. Combined with expertise to calculate the inhomogeneous response for a single realization of disorder, the goal is to generate universal phase diagrams in multi-parameter space. By following both materials- and computation- inspired routes, accelerated discovery of materials with desired optimized functionalities by an iterative feedback loop is inevitable. Some of the expected major breakthroughs from this project are: (1) Discovery and optimization of novel electronic phases with unusual magneto-transport properties. (2) Discovery of topologically protected surface states in the background of textured magnetic phases, revealing phenomena richer than topological band insulators. (3) Emergence of new paradigms for superconductivity in insulators or multi-band low density TMDCs, beyond the standard BCS theory of a Fermi surface instability. (4) The detection of spatially periodically modulated superconducting phases in strongly spin-orbit coupled systems. (5) Synthesis of new and optimization of existing materials with desired functionalities by tuning chemistry, strain and electric field gating.