DATE: Tuesday, March 10, 2026
TIME: 11:00 a.m. – 1:00 p.m. ET
LOCATION: MIT.nano, 12-0168
SPEAKERS: Dr. John Gaida, CEO and co-founder of QSEM GmbH; and Dr. John Simonaitis, MIT PhD '25
ABSTRACTs
11:00 a.m. – 11:45 a.m.: A Platform for Multimodal Ultrafast Scanning Electron Microscopy
Presented by Dr. John Gaida
Gaida will present the Quantum Scanning Electron Microscope (QSEM), a newly developed multimodal ultrafast electron microscope designed to probe material dynamics and quantum optical phenomena with high spatial and temporal resolution. Ultrafast electron microscopy enables femtosecond‑scale access to out‑of‑equilibrium structural and electronic processes at the nanoscale. QSEM employs femtosecond‑pulsed linear photoemission from a Schottky field emitter and offers simultaneous transmission, reflection, and secondary‑electron detection across 100 eV–30 keV. By bringing femtosecond temporal resolution and fully multimodal detection to the SEM architecture, QSEM establishes a new approach for ultrafast measurements and additionally will enable advanced modes such as energy‑filtered imaging, electron spectroscopy, cathodoluminescence and correlated electron–light detection schemes. As an initial demonstration, raster‑scanned nanobeam diffraction resolves nanoscale structural heterogeneity in the layered quantum material 1T‑TaSe₂. Together, these capabilities position QSEM as a versatile platform for ultrafast investigations of structural, electronic, and quantum‑optical phenomena in advanced materials, as well as quantum-coherent electron–light interactions.
11:45 a.m. – 12:30 p.m.: Quantum-Coherent SEM-EELS: Achieving Optimal Measurements in Low-Dimensional, Nanophotonic, and Quantum Systems
Presented by Dr. John Simonaitis
Recent advances in 2D materials, energy/catalytic materials, and nanophotonics have driven the need for high-resolution electron spectroscopy. While Transmission Electron Microscope-based Electron Energy Loss Spectroscopy (TEM-EELS) provides sub-nanometer and femtosecond resolution, the >100 keV relativistic energy of TEM electrons limits this approach in two ways - (1) significant knock-on damage, and (2) weak coupling.
In this work, Simonaitis and his colleagues experimentally demonstrate that low-energy EELS performed in a Scanning Electron Microscope (SEM) overcomes these barriers. They show that SEM-EELS enables knock-on damage-free measurements while achieving >50x stronger coupling to both 2D and nananophotonic systems compared to TEM-EELS. They further explore the applications of this high-efficiency technique for studying energetic and catalytic materials and nm-scale, quantum-coherent readout of nitrogen/silicon vacancy centers, quantum dots. They finish by examining this technologies potential for the generation of exotic states of quantum light.
Speaker Bios
Dr. John Gaida studied physics at the University of Göttingen and the Politecnico di Milano. Since 2017, he has worked in ultrafast electron microscopy. He completed his PhD summa cum laude in 2024 with the thesis “Coherent Attosecond Electron Microscopy” under Prof. Claus Ropers, earning the Jan-Peter Toennies Physics PhD Prize. He is the CEO and co-founder of QSEM GmbH, a Max Planck spin-off developing ultrafast electron microscopy solutions, including the multimodal ultrafast scanning electron microscope QSEM|1, designed for quantum experiments using free electrons and laser light.
Dr. John Simonaitis studied electrical engineering in the Research Laboratory of Electronics at MIT under Prof. Karl Berggren and Phillip "Donnie" Keathley. His thesis was on the topic of low-energy electron photon interactions in scanning electron microscopes (SEMs), leading a Deshpande Momentum Grant funded post-doc to commercialize these SEM-integrated electron energy loss spectrometers.