Two-electron ARPES

Two-electron ARPES (2e-ARPES) extends the scope of conventional photoemission by using coincidence detection to measure two electrons emitted simultaneously from a correlated many-body state. Whereas traditional ARPES probes the single-particle spectral function, 2e-ARPES provides access to genuinely two-particle correlations that remain hidden in standard photoemission measurements. By detecting both electrons in coincidence and reconstructing their energies and momenta, one can infer the total momentum and internal structure of the emitted pair, opening a direct experimental window onto the underlying two-particle wavefunction. This makes 2e-ARPES especially promising for the study of unconventional superconductors and other strongly correlated systems, where the essential physics is encoded not only in the behavior of individual quasiparticles but also in the structure of their paired or collective states.

Our group is developing first-of-its-kind 2e-ARPES instrumentation and methodology based on an energy-filtered time-of-flight momentum microscope, with the goal of directly probing correlated electron pairs and revealing the internal momentum-space structure of Cooper pairs in high-temperature superconductors.