Equipment: MRI Track 1: Development of an Atomic-Resolution Microwave Microscope

Nontechnical Description: The goal of this project is the development of a new type of microscope that can image materials with unprecedented spatial and temporal resolution. The new instrument is called an atomic resolution microwave microscope (ARMM) and is designed to have the capability of imaging fast moving electrons in electrical devices down to the atomic scale. Current state of the art microscopes can only visualize the atomic structure of devices when electrons are moving very slowly. This is inadequate for modern technology where there is need to not only visualize electrons at very small length scales (due to the relentless miniaturization of electrical devices), but also to visualize their behavior when they move very fast (due to the ever-increasing speed of modern technology). The new ARMM instrument is designed to image electrons when they move at speeds that allow them to orbit a device billions of times per second. These are called “microwave frequencies” and this frequency range is critical for many modern technological applications and quantum science discoveries. In order to develop more highly efficient electrical devices that can operate at these frequencies it is important to develop microscopes that can probe new materials in this regime. The ARMM instrument fulfills this need. Technical Description: The key capabilities of the new atomic-resolution microwave microscope (ARMM) include combined atomically resolved imaging and local microwave characterization of 2D devices. The new instrument is designed to operate at cryogenic temperatures in ultrahigh vacuum while integrating scanning tunneling microscopy, atomic force microscopy, microwave impedance microscopy (MIM), and electron spin resonance detection (STM ESR), all using the same probe tip. MIM and STM ESR will allow measurement of local high-frequency complex permittivity and spin resonance behavior. Major research projects involve the determination of how 2D Wigner crystals melt in inhomogeneous disordered environments, including spatial resolution of new solid/liquid electronic phases coexisting with atomic-scale defects. Other important research targets involve characterization of the quantum magnetism of 1D Wigner chains, 0D Wigner molecules, and topological boundary modes. Direct measurement of quantum coherence times for individual defects in 2D devices is designed to enable their evaluation as potential qubits. The goals and scope of this project include the design, testing, and fabrication of new radio frequency (rf) circuit components. This involves impedance matching to the tip assembly, installation of cryogenic microwave amplifier components, and the construction of a new rf compatible sample holder. Design and fabrication phases, as well as ARMM software development, precede final assembly and commissioning phases. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2511470 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Michael Crommie | Institution: University of California-Berkeley, BERKELEY, CA | Award Amount: $736,024 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2511470 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2511470.html