Carnegie Mellon University


National Science Foundation, Major Research Instrumentation Award: Acquisition of Low-Temperature Scanning Tunneling Microscope

Five investigators from Carnegie Mellon University – Feenstra, Gellman, Hunt, Majetich, and Skowronski – have acquired a low-temperature scanning tunneling microscope (LT-STM), including magnetic field capability. The total project cost is $662K, of which 30% is cost shared.

Intellectual Merit – Two-dimensional (2D) materials and heterostructures will be studied. 2D materials, which are only one or a few atomic layers thick, are formed by “exfoliation” from bulk crystals, that is, peeling off one or a few atomic layers from a bulk crystal and depositing those layer(s) on a suitable inert substrate. Such 2D layers exhibit a host of exotic properties including massless fermions, topologically protected states, superconductivity, and ferromagnetic phases, all of which will be probed in the LT-STM. Additionally vertical heterostructures will be formed by transferring one atomic layer atop the other; a state-of-the-art facility for performing such fabrication exists at CMU. Properties of the materials can be controlled in such heterostructures, since the presence of one layer in proximity to another yields collective behavior that differs from that of the individual layers.

 Broader Impact – All of the investigators are active in directing graduate and undergraduate research, and the LT-STM instrument will significantly enhance those activities. Additionally, the facility will impact theoretical studies presently performed at CMU related to the experimental work of the investigators. The instrument is also expected to have significant impact on the “Center for 2D Materials and Devices for Energy-Efficient Computing” at CMU, which four of the PIs are members of. An operating plan for the LT-STM has been formulated that will permit external users to have access to it. Four of the investigators are members of the “Pittsburgh Quantum Institute”, which includes about 50 faculty from University of Pittsburgh, CMU, and Dusquesne University. The LT-STM will serve as a powerful characterization tool for research projects undertaken by members of this Institute.