Photoinduced changes of the chemical potential in superconducting BiSrCaCuO
arXiv:1510.06457 · doi:10.1103/PhysRevB.92.144506
Abstract
The chemical potential of a superconductor is of critical importance since, at equilibrium, it is the energy where electrons pair and form the superconducting condensate. However, in non-equilibrium measurements, there may be a difference between the chemical potential of the quasiparticles and that of the pairs. Here we report a systematic time- and angle-resolved photoemission study of the pump-induced change in the chemical potential of an optimally doped BiSrCaCuO (Bi2212) sample in both its normal and superconducting states. The change in chemical potential can be understood by separately considering the change in the valence band energy relative to the vacuum, and the change in chemical potential relative to the valence band energy. We attribute the former effect to a changing potential barrier at the sample surface, and the latter effect to the conservation of charge in an asymmetrical density of states. The results indicate that the pair and quasiparticle chemical potentials follow each other even on picosecond timescales.
6 pages, 4 figures
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Cited by in corpus (10)
- Time- and Angle-Resolved Photoemission Studies of Quantum Materials
- Ultrafast Angle-Resolved Photoemission Spectroscopy of Quantum Materials
- Time-resolved ARPES on cuprates: Tracking the low-energy electrodynamics in the time domain
- Population inversion and Dirac fermion cooling in 3D Dirac semimetal CdAs
- Influence of Optically Quenched Superconductivity on Quasiparticle Relaxation Rates in Bi2Sr2CaCu2O8+delta
- Particle-hole Asymmetry in the Cuprate Pseudogap Measured with Time-Resolved Spectroscopy
- Nonequilibrium Electron Dynamics in a Solid with a Changing Nodal Excitation Gap
- The role of the chemical potential in the BCS theory
- Photoinduced filling of near nodal gap in BiSrCaCuO
- Ultrafast Raman probe of the photoinduced superconducting to normal state transition in the cuprate BiSrCaCuO