APPLICATIONS OF TECHNOLOGY:
- Electron spectroscopy
- Electron microscopy
- Materials research for development of spintronic, solid-state data storage and data processing devices
- Improves efficiency by up to 100 times
- Offers superior efficiency and resolutions at a wide range of photon energies
- Spin polarimeter component adds spin resolution to commercial instruments
Scientists at Berkeley Lab have invented a high-efficiency photoemission spectrometer, or electron energy analyzer, with spin resolution. Because the invention measures energy, angle and spin, it is ideal for analyzing the spin-dependent electronic structure of materials for the electronics, computing and semiconductor industries.
The Berkeley Lab technology achieves high efficiency and resolution by combining two alternate approaches to measuring electronic properties. First, it uses a custom, low-energy, exchange scattering polarimeter, in contrast to a typical, high-energy Mott scattering polarimeter. Second, it integrates the polarimeter within a time-of-flight (TOF) based energy analysis scheme with a flexible, high quality electrostatic lens system to provide parallel, multichannel energy analysis.
An integrated 90-degree bandpass filter enables a particular region of interest in a sample’s emitted spectrum to be targeted and measured with high-energy resolution. This feature simultaneously removes unwanted portions of the spectrum and enables use with higher photon energy and/or repetition rates than would otherwise be compatible with TOF techniques. By combining TOF with a 90-degree bandpass filter, the invention makes spin- and angle-resolved photoemission spectroscopy possible using pulsed laser, Harmonic Generation (HHG) laser, pulsed synchrotron, and Free-Electron Laser (FEL) light sources. When used with these light sources, the study of ultrafast properties of condensed matter is also possible.
In addition to operating as a stand-alone device, the spin polarimeter component can be used with other commercial electron energy analyzers to conduct photoemission experiments. Further, the component can be added to different commercial instruments that need spin resolution, such as a scanning electron microscope (SEM) modified to become a high efficiency scanning electron microscope with polarization analysis (SEMPA).State-of-the-art spin-resolved spectrometers employ a high-energy scattering process that detects only a small percentage (less than 0.1%) of the electron beam. This slow and difficult technique is impractical for measuring the distribution of electrons photoemitted from a sample with respect to spin, energy, and angle at resolutions required for in-depth materials analysis. The Berkeley Lab photoemission spectrometer / spin polarimeter can measure the spin polarization of electron beams 100 times more efficiently than current devices.
DEVELOPMENT STAGE: Industrial prototype.
STATUS: Patent pending. Available for licensing or collaborative research.
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REFERENCE NUMBER: IB-2695