Dr. Osip Schwartz
Department of Physics of Complex Systems, Weizmann Institute of Science
In recent years, transmission electron microscopy (TEM) revolutionized structural biology by enabling protein structure determination directly from TEM images of protein particles. The main remaining limitation in life science TEM is the extremely poor signal-to-noise ratio. The images are noisy because biological samples are highly sensitive to electron beam exposure, which severely limits the number of electrons per unit area, leading to a high shot noise. Although this problem appears fundamental, I will show that it can be addressed using the tools and concepts of quantum physics, such as laser-based control of electron wave functions and quantum metrology.
In addition, some of the tools we develop for this purpose can be used for fundamental physics exploration. Although in classical physics electromagnetic waves do not interact with each other, in quantum physics, photons can interact by exchanging virtual particles, which results in the physical vacuum behaving as a weakly nonlinear electromagnetic medium. The electromagnetic nonlinearity of vacuum due to the creation and annihilation of virtual electron-positron pairs in a strong electromagnetic field was predicted more than eighty years ago but is yet to be directly measured in the laboratory. We aim to measure this fundamental property of the physical vacuum in a small-scale (tabletop) laser-based experiment within a few years.