Condensed Matter/Materials & Biological Physics Seminar with Juan Carlos Idrobo

Scanning transmission electron microscopy (STEM), when combined with electron energy-loss spectroscopy (EELS), has the potential to detect properties associated with quantum materials with unprecedented spatial resolution. These properties include the emergence of magnetic ordering, valley polarization, phonon chirality, and topological characteristics such as Hall effects. Idrobo and his collaborators have shown that achieving such measurements requires a configuration that ensures that electron momentum transfer in EELS mimics the role of polarization in light and X-rays.

He will present a broad overview of what electron microscopy can now routinely achieve in understanding material physics, as well as an example illustrating how orbital angular momentum, through the orbital Hall effect (OHE), can be detected and characterized at the nanometer scale. Subsequently, he will delve into the detection of chiral phonons at the nanoscale and the prerequisites for achieving two-dimensional isotopic mapping with sub-nanometer accuracy. Throughout the talk, Idrobo will showcase experimental findings on these subjects and explore how their detection is ushering in a new era in materials characterization