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arXiv · 1612.04910

Time-resolved photoemission apparatus achieving sub-20-meV energy resolution and high stability

Y. Ishida·T. Togashi·K. Yamamoto·M. Tanaka·T. Kiss·T. Otsu·Y. Kobayashi·S. Shin
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Abstract

The paper describes a time- and angle-resolved photoemission apparatus consisting of a hemispherical analyzer and a pulsed laser source. We demonstrate 1.48-eV pump and 5.90-eV probe measurements at the >10.5-meV and >240-fs resolutions by use of fairly monochromatic 170-fs pulses delivered from a regeneratively amplified Ti:sapphire laser system operating typically at 250 kHz. The apparatus is capable to resolve the optically filled superconducting peak in the unoccupied states of a cuprate superconductor, Bi2Sr2CaCu2O8+d. A dataset recorded on Bi(111) surface is also presented. Technical descriptions include the followings: A simple procedure to fine-tune the spatio-temporal overlap of the pump-and-probe beams and their diameters; achieving a long-term stability of the system that enables a normalization-free dataset acquisition; changing the repetition rate by utilizing acoustic optical modulator and frequency-division circuit.

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Y. Ishida, T. Togashi, K. Yamamoto, M. Tanaka, T. Kiss, T. Otsu, Y. Kobayashi, S. Shin. 2016-12-15. Time-resolved photoemission apparatus achieving sub-20-meV energy resolution and high stability. https://doi.org/10.1063/1.4903788

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