Novel probes of collective excitations

The goal of this project is to propose signatures of excitations in many-body systems using novel measurement techniques, such as state-of-the-art scanning probe sensors. I am particularly interested in modes that are hard to detect in conventional experiments, e.g., because they do not have a charge response.

One example are shear-wave excitations of electrons in metals (i.e., ’transverse plasmons’), which do not have charge fluctuations and therefore do not couple to light. Nevertheless such modes can become bright either in confined geometry or in a magnetic field, such that they can be detected by spectroscopy or with scanning near-field optical microscopes.

As another direction, I am interested in using NV centers in diamond to characterize spinon Fermi surface states or to determine the spectrum of two-dimensional magnets, which are hard to assess with other techniques. Moreover, I am interested in thermal transport signatures, e.g., of broken-symmetry states in quantum Hall ferromagnets.