Realizing and Manipulating Magnetism and Transport in Two-Dimensional Transition Metal Dichalcogenides

Indiana University, Bloomington IN

Investigators

Abstract

Non-technical description: The atomically thin transition metal dichalcogenides have recently emerged as a novel class of two-dimensional semiconductors that possess remarkable physical properties and promising opportunities for electronic and optoelectronic applications. While significant progress has been made, including the fabrication of high performance devices, most studies so far have mainly focused on the charge property of electrons. Adding electron's spin and valley properties to charge-based electronic systems could add substantially more exotic physical phenomena and enhanced capability in devices. This research project aims to produce two-dimensional ferromagnetic semiconductors using transition metal dichalcogenides and study their spin and valley transport properties. Such ferromagnetic semiconductors host the key ingredients for both information storage (magnetism) and information processing (semiconductors). This research could facilitate the discovery of new physics associated with the electron's spin and valley properties, and may create opportunities for practical applications of novel two-dimensional materials in the area of modern information technology. The project involves considerable education and training of graduate and undergraduate students, including those from the underrepresented groups. It is also integrated with a unique educational project that aims to help improve the K-12 education in local schools in rural areas near Indiana University. Technical description: This research project aims to realize and manipulate magnetism and spin & valley transport in a new class of two-dimensional crystals, i.e. atomically thin transition metal dichalcogenides. The experimental activities include the realization of ferromagnetism by chemical doping and defect creation, electrical probing of spin Hall effect and valley Hall effect, and manipulation of both magnetic and transport properties through electric field effect and elastic strain engineering. Theoretical studies are strongly correlated with the experimental activities. The project encompasses nanomaterial synthesis, device fabrication, magnetic characterization, Hall effect measurement, strain engineering and theoretical modeling, and is a collaborative effort between two Indiana University faculty. It could provide significant insight into the roles that the charge carriers, spin-orbit coupling, and electronic band structure play in determining the magnetic and transport properties of these novel two-dimensional materials. The project also involves considerable education and training of graduate and undergraduate students, including those from the underrepresented groups, to help them develop various skills and techniques necessary for their future careers in the broad area of material science and nanotechnology. It is also integrated with a unique educational project that aims to help improve the K-12 education in local schools in rural areas near Indiana University.