Visualization of spin-polarized electronic states by imaging-type spin-resolved photoemission microscopy

ABSTRACT

Harnessing electron spin is crucial in developing energy-saving and high-speed devices for the next generation. In this scheme, visualizing spin-polarized electronic states aids in designing and developing new materials and devices. Spin-resolved photoemission spectroscopy provides information on the spin-polarized electronic states. To investigate the spin-polarized electronic states in microscopic materials and devices, spin-resolved photoemission spectroscopy requires spatial resolution in a sub-micrometer scale. Here we show the imaging-type spin-resolved photoemission microscopy (iSPEM) with an ultraviolet laser developed at the National Institutes for Materials Science (NIMS). Our iSPEM achieves a spatial resolution of 420 nm, drastically improving by more than an order of magnitude compared to conventional spin-resolved photoemission spectroscopy instruments. Besides, the multichannel spin detector significantly reduces the data acquisition time by four orders of magnitude compared to the conventional instruments. The iSPEM machine elucidates the spin-polarized electronic states of sub-micrometer scale materials, polycrystals, device structure samples, and so on, which have yet to be the target of conventional spin-resolved photoemission spectroscopy.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

We have developed an imaging-type spin-resolved photoemission microscopy machine, realizing quick visualization of the spin-polarized electronic states of materials both in real and momentum spaces.

KEYWORDS:

• Spin-resolved photoemission microscopy
• spin-polarized electronic state
• high spatial resolution
• multichannel spin detection

Acknowledgements

The authors thank Nils Weber and Fumiya Arai for their technical support in developing the spectrometer. The authors also thank Shingo Takezawa for technical support in preparing the Bi/Ge(111) sample.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/27660400.2024.2328206

Additional information

Funding

The present work was partially supported by the Japan Society for the Promotion of Science KAKENHI [Grant Nos. JP21K04633 and JP22H01761], the Innovative Science and Technology Initiative for Security Grant Number JPJ004596, ATLA, Japan, and Iketani Science and Technology Foundation.