Abstract Details - Hongyu Xiong

Development of the next generation of spin-resolved photoemission spectroscopy
Presenter Hongyu Xiong
Presentation Type Poster
Full Author List

Hongyu Xiong, Jonathan Sobota, Chris Jozwiak, Patrick Kirchmann, Zahid Hussain & Zhi-Xun Shen

Affiliations

Stanford University and SLAC National Accelerator Laboratory

Abstract Angle-resolved photoemission spectroscopy (ARPES) is an experimental technique for directly probing electronic band structure, which reveals important electronic properties of materials.  Additional material properties related to magnetism and spin-orbital coupling are encoded in spin, an intrinsic quantum number of electrons. However, ARPES itself cannot resolve spin, thus providing limited information when these effects are significant, such as in magnetic materials and topological insulators. We are therefore constructing a spin-resolved ARPES system using a novel detector known as the spin-resolved Time-of-Flight (spin-TOF). The main advantage of the spin-TOF detector is its efficiency. Traditional spin detectors can only measure the spin polarization at a chosen electron energy and chosen momentum (a single pixel of a 2D energy-momentum plot) at a time. In contrast, the spin-TOF is able to obtain the polarization of a wide range of electron energy at a chosen momentum (a vertical array of the 2D plot), thus significantly increasing the data recording efficiency. The light source we are using for photoemission is a laser with 11eV photon energy. This photon energy allows us to access a larger range of momentum space than conventional 6eV lasers, i.e. up to k ~ 1.2 angstrom^(-1). This new laser will enable us to study not only conventional magnetic materials and materials with strong spin-orbit coupling, but also materials with potential application in spintronics and valleytronics, such as transition-metal dichalcogenides, and unconventional superconductors.