151 research outputs found
Time-, spin-, and angle-resolved photoemission spectroscopy with a 1-MHz 10.7-eV pulse laser
We describe a setup of time-, spin-, and angle-resolved photoemission
spectroscopy (tr-SARPES) employing a 10.7-eV (=115.6 nm) pulse laser
at 1-MHz repetition rate as a probe photon source. This equipment effectively
combines technologies of a high-power Yb:fiber laser, ultraviolet-driven
harmonic generation in Xe gas, and a SARPES apparatus equipped with
very-low-energy-electron-diffraction (VLEED) spin detectors. A high repetition
rate (1 MHz) of the probe laser allows experiments with the photoemission
space-charge effects significantly reduced, despite a high flux of 10
photons/s on the sample. The relatively high photon energy (10.7 eV) also
brings the capability of observing a wide momentum range that covers the entire
Brillouin zone of many materials while ensuring high momentum resolution. The
experimental setup overcomes a low efficiency of spin-resolved measurements,
which gets even more severe for the pump-probed unoccupied states, and affords
for investigating ultrafast electron and spin dynamics of modern quantum
materials with energy and time resolutions of 25 meV and 360 fs, respectively.Comment: 11 pages, 7 figure
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