This project is awarded under the Nanoelectronics for 2020 and Beyond competition, with support by multiple Directorates and Divisions at the National Science Foundation as well as by the Nanoelectronics Research Initiative of the Semiconductor Research Corporation.
The search for high-performance electronic switches operating at low power dissipation has generated many concepts that go beyond the control of charge flow in traditional semiconductor device structures. These novel devices are based on the use of alternative state variables, including the characteristics of single-particle quantum systems, such as spin, pseudospin, and carrier wave-function phase, and the characteristics of correlated many-body quantum systems, such as excitons and exciton condensates. The goal of this project is to develop the basis for transformative technology that would be made possible by the availability of high-performance electronic devices employing such quantum state variables, rather than traditional semi-classical transport of charge. To this end, a team of investigators at Columbia University and University of Florida is devoted to the fabrication, characterization, and theoretical analysis of such quantum switches. The research exploits recent technological advances in the synthesis of atomically thin layers of van der Waals solids and heterostructures formed from combinations of such layered materials. The potential of this approach is exemplified by the excellent electrical characteristics exhibited by heterostructures of atomically thin layers of graphene and hexagonal boron nitride. In this project, devices are built from such well-developed material systems, where the primary fabrication challenges involve precise control over geometry and interface cleanliness. The key research components of the project are as follows: (i) The assembly and fabrication of atomically thin heterostructure devices based on the co-lamination of van der Waals materials, atomic-layer deposition processes, and advanced patterning techniques; (ii) the analysis of distinctive quantum coherent transport processes in weakly coupled layered heterojunction device structures by electrical and optical measurements; (iii) the establishment of new state variables based on quantum coherence; and (iv) the demonstration, characterization, and theoretical modeling of switching devices based on novel state variables. Devices resulting from this research effort promise performance with respect to switching speed and energy dissipation that significantly exceeds the limits imposed by conventional semiconductor device technology.
The development of the new electronic devices based on low-dimensional functional material platforms opens important directions in both fundamental and applied research. The availability of practical high-performance, low-energy switching devices is of great significance for the continued advancement of electronics and the associated information technology industry. Thus, the demonstration of devices based on new switching principles has the potential for broad technological impact. The diverse capabilities of the team also significantly enhance the educational opportunities for students and postdocs at Columbia and at collaborating institutions. The highly interdisciplinary research carried out in this project provides cutting-edge training for graduate students and postdocs, as well as for undergraduate students. The team integrates research activities with educational efforts by offering new lecture and laboratory courses, as well as modifying existing ones. The team also undertakes broader educational outreach through sponsorship of summer research projects for high school students. Significant efforts are made toward K-12 outreach by training of highly motivated high school students, and by enhancing interactions with local K-12 educators to introduce front-line research to students.
