Events Calendar

Speaker: Hongkun Park, Harvard University

Title: Drawing “Quantum” on an Atomically Thin Canvas

Abstract: Recent advances in materials growth and fabrication have enabled the preparation of high-quality van der Waals heterostructures made of two-dimensional materials, such as graphene and transition metal dichalcogenide monolayers. In this presentation, I will describe our efforts to use these heterostructures as a "canvas" to realize new quantum optoelectronic devices for excitons and electrons and use them for quantum simulation. I will discuss how we improve the exciton's spectral/spatial uniformity and coherence and realize atomically thin mirrors and active metasurfaces. I will then describe the realization of electron Wigner crystal phases in these heterostructures without a magnetic field or moiré potential. I will present experimental evidence for long-standing theoretical predictions that the density-driven quantum melting of a Wigner crystal proceeds through intermediate phases characterized by a microscopic coexistence of crystal and liquid states. Our studies illustrate that the atomically thin heterostructures are an attractive solid-state platform for realizing solid-state quantum simulators and exploring novel excitonic and correlated electron phenomena.

Bio: Hongkun Park is Mark Hyman Jr. Professor of Chemistry and Professor of Physics at Harvard University. He is also a Member of the Harvard Quantum Science and Engineering Graduate Program, Broad Institute of Harvard and MIT, Harvard Center for Brain Science, and Harvard Stem Cell Institute. His current research group focuses on fundamental studies of nanoscale electrical, optical, and plasmonic devices that operate based upon quantum mechanical principles as well as the development of new nano- and microelectronic tools that can interface with living cells, cell networks, and organisms. The goal of his quantum optoelectronics effort is to develop solid-state optoelectronic devices that work all the way down to the single quantum level, thus paving the way for all-optical computing and solid-state quantum information processing. His nano-bio interfacing effort is geared toward developing new nanoscale tools for interrogating living cells and cell networks, with the focus in illuminating the inner workings of the brain. He is also developing ultra-sensitive magnetic, electric, and temperature sensors based on diamond color centers and using them to address various problems spanning condensed matter physics, molecular structural determination, and biological sensing. Awards and honors that Hongkun Park has received include Ho-Am Foundation Prize in Science, NIH Director's Pioneer Award, US Department of Defense Vannevar Bush Faculty Fellowship, David and Lucile Packard Foundation Fellowship, Alfred P. Sloan Research Fellowship, The Scientist of the Year Award by KSEA, Camille Dreyfus Teacher-Scholar Award, Kavli Lectureship from the Delft University of Technology, A. R. Gordon Distinguished Lectureship at the University of Toronto, and William Draper Harkins Lectureship at the University of Chicago. He is elected to the American Academy of Arts and Sciences and the American Association for the Advancement of Science.