Scanning nuclear resonance imaging of a hyperfine-coupled quantum Hall system

• Published in: Nature communications Vol. 9; no. 1; pp. 2215 - 7
• Main Authors: Hashimoto, Katsushi, Tomimatsu, Toru, Sato, Ken, Hirayama, Yoshiro
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.06.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 147/136; 639/301/930/2735; 639/925/930/2735; 639/925/930/878/1264; Conduction; Conduction electrons; Electron gas; Electron spin; Electrons; Humanities and Social Sciences; Magnetic fields; Magnetic resonance; multidisciplinary; NMR; Nuclear magnetic resonance; Nuclear spin; Polarization; Polarization (spin alignment); Quantum Hall effect; Resonance; Scanning; Science; Science (multidisciplinary); Spatial distribution
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04612-y

Nuclear resonance (NR) is widely used to detect and characterise nuclear spin polarisation and conduction electron spin polarisation coupled by a hyperfine interaction. While the macroscopic aspects of such hyperfine-coupled systems have been addressed in most relevant studies, the essential role of local variation in both types of spin polarisation has been indicated in 2D semiconductor systems. In this study, we apply a recently developed local and highly sensitive NR based on a scanning probe to a hyperfine-coupled quantum Hall (QH) system in a 2D electron gas subject to a strong magnetic field. We succeed in imaging the NR intensity and Knight shift, uncovering the spatial distribution of both the nuclear and electron spin polarisation. The results reveal the microscopic origin of the nonequilibrium QH phenomena, and highlight the potential use of our technique in microscopic studies on various electron spin systems as well as their correlations with nuclear spins. Exploring the hyperfine-coupled quantum Hall (QH) system facilitates the nuclear spintronic applications. Here the authors reveal the origin of the nonequilibrium QH phenomena by mapping the spatial distribution of nuclear and electron spin polarization in a GaAs quantum well with scanning probe incorporated nuclear resonance technique.