Stahl C, Eckstein M (2019)
Publication Type: Journal article
Publication year: 2019
Book Volume: 99
Journal Issue: 24
DOI: 10.1103/PhysRevB.99.241111
In time-resolved photoemission experiments, more than one electron can be emitted from the solid by a single ultrashort pulse. We theoretically demonstrate how correlations between the momenta of outgoing electrons relate to time-dependent two-particle correlations in the solid. This can extend the scope of time-and angle-resolved photoemission spectroscopy to probe superconducting and charge density fluctuations in systems without long-range order, and to reveal their dynamics independent of the electronic gap and thus unrestricted by the energy-time uncertainty. The proposal is illustrated for superconductivity in a BCS model. An impulsive perturbation can quench the gap on ultrafast timescales, while nonequilibrium pairing correlations persist much longer, even when electron-electron scattering beyond mean-field theory is taken into account. There is thus a clear distinction between a dephasing of the Cooper pairs and the thermalization into the normal state. While a measurement of the gap would be blind to such pairing correlations, they can be revealed by the angular correlations in photoemission.
APA:
Stahl, C., & Eckstein, M. (2019). Noise correlations in time- and angle-resolved photoemission spectroscopy. Physical Review B, 99(24). https://dx.doi.org/10.1103/PhysRevB.99.241111
MLA:
Stahl, Christopher, and Martin Eckstein. "Noise correlations in time- and angle-resolved photoemission spectroscopy." Physical Review B 99.24 (2019).
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