Exploring quantum materials with ultrafast photoemission spectroscopy

Woojoo Lee

Time- and angle-resolved photoemission spectroscopy (trARPES) offers powerful means to directly visualize non-equilibrium electronic states of quantum materials. The technique combines angle-resolved photoemission spectroscopy (ARPES) with ultrafast pump-probe spectroscopy. Specifically, trARPES perturbs a target system with a pump pulse and then ejects electrons from the photoexcited state using a subsequent probe pulse. This enables the transient visualization of non-equilibrium electronic states in energy-momentum space. Such visualization provides valuable insights into unoccupied states, electron-coherent phonon coupling, quantum phase transitions, electron dynamics, and Floquet states. In this presentation, I will discuss cutting-edge research on quantum materials (magnetic topological insulator and monolayer TMDs) using trARPES.