A high-efficiency spin-resolved photoemission spectrometer combining time-of-flight spectroscopy with exchange-scattering polarimetry

Journal Article · Tue Apr 13 00:00:00 EDT 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3427223· OSTI ID:983788

Jozwiak, Chris M; Graff, Jeff; Lebedev, Gennadi; Andresen, Nord; Schmid, Andreas; Fedorov, Alexei; El Gabaly, Farid; Wan, Weishi; Lanzara, Alessandra; Hussain, Zahid

We describe a spin-resolved electron spectrometer capable of uniquely efficient and high energy resolution measurements. Spin analysis is obtained through polarimetry based on low-energy exchange scattering from a ferromagnetic thin-film target. This approach can achieve a similar analyzing power (Sherman function) as state-of-the-art Mott scattering polarimeters, but with as much as 100 times improved efficiency due to increased reflectivity. Performance is further enhanced by integrating the polarimeter into a time-of-flight (TOF) based energy analysis scheme with a precise and flexible electrostatic lens system. The parallel acquisition of a range of electron kinetic energies afforded by the TOF approach results in an order of magnitude (or more) increase in efficiency compared to hemispherical analyzers. The lens system additionally features a 90 degrees bandpass filter, which by removing unwanted parts of the photoelectron distribution allows the TOF technique to be performed at low electron drift energy and high energy resolution within a wide range of experimental parameters. The spectrometer is ideally suited for high-resolution spin- and angle-resolved photoemission spectroscopy (spin-ARPES), and initial results are shown. The TOF approach makes the spectrometer especially ideal for time-resolved spin-ARPES experiments.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: Advanced Light Source Division; Materials Sciences Division
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 983788
• Report Number(s): LBNL-3530E; TRN: US201015%%1326
• Journal Information: Review of Scientific Instruments, Vol. 81, Issue 5
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
47 OTHER INSTRUMENTATION
36 MATERIALS SCIENCE
EFFICIENCY
ELECTRON DRIFT
ELECTRON SPECTROMETERS
ENERGY
ENERGY ANALYSIS
ENERGY RESOLUTION
MOTT SCATTERING
PHOTOEMISSION
POLARIMETRY
POLARIZATION-ASYMMETRY RATIO
SCATTERING
SPECTROMETERS
SPECTROSCOPY
SPIN
photoemission spectroscopy
spin-resolved
polarimetry
exchange scattering
ARPES
time-of-flight
TOF