Ultrafast interrogation of quantum materials

Abstract Developments in non-linear ultrafast spectroscopy allow us to probe many body quantum dynamics in the solid state, yielding novel insights into quantum materials. I highlight key advances in this emerging field, including the application of non-linear spectroscopic techniques to resolve longstanding open problems in silicon, and proposals to use such techniques for diagnosis and characterization of fractionalized excitations in quantum spin liquids and beyond.

Refs: Observation of a marginal Fermi glass. Fahad Mahmood, Dipanjan Chaudhuri, Sarang Gopalakrishnan, Rahul Nandkishore, N. P. Armitage, Nature Physics 17, 627-631 (2021).
Spectroscopic fingerprints of gapped quantum spin liquids, both conventional and fractonic. Rahul M. Nandkishore, Wonjune Choi and Yong-Baek Kim, Phys. Rev. Research 3, 013254 (2021)
Extracting spinon self-energies from two-dimensional coherent spectroscopy. Oliver Hart and Rahul Nandkishore, arXiv: 2208.12817.