Chirality‐Induced Magnet‐Free Spin Generation in a Semiconductor

• DOI: 10.1002/adma.202406347
• Publication Date: 2024-06-27T04:39:35Z
• Authors: Tianhan Liu; Yuwaraj Adhikari; Hailong Wang; Yiyang Jiang; Zhenqi Hua; Haoyang Liu; Pedro Schlottmann; Hanwei Gao; Paul S. Weiss; Binghai Yan; Jianhua Zhao; Peng Xiong
• Keywords: molecular junctions; molecular spintronics; Condensed Matter - Materials Science; Quantum Physics; Condensed Matter - Mesoscale and Nanoscale Physics; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 02 engineering and technology; Condensed Matter Physics; spin transport; Hanle effect; Physical sciences; chirality‐induced spin selectivity; Engineering; Chemical sciences; Physical Sciences; Chemical Sciences; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); chirality-induced spin selectivity; Nanoscience & Nanotechnology; Quantum Physics (quant-ph); 0210 nano-technology

AbstractElectrical generation and transduction of polarized electron spins in semiconductors (SCs) are of central interest in spintronics and quantum information science. While spin generation in SCs is frequently realized via electrical injection from a ferromagnet (FM), there are significant advantages in nonmagnetic pathways of creating spin polarization. One such pathway exploits the interplay of electron spin with chirality in electronic structures or real space. Here, utilizing chirality‐induced spin selectivity (CISS), the efficient creation of spin accumulation in n‐doped GaAs via electric current injection from a normal metal (Au) electrode through a self‐assembled monolayer (SAM) of chiral molecules (α‐helix l‐polyalanine, AHPA‐L), is demonstrated. The resulting spin polarization is detected as a Hanle effect in the n‐GaAs, which is found to obey a distinct universal scaling with temperature and bias current consistent with chirality‐induced spin accumulation. The experiment constitutes a definitive observation of CISS in a fully nonmagnetic device structure and demonstration of its ability to generate spin accumulation in a conventional SC. The results thus place key constraints on the physical mechanism of CISS and present a new scheme for magnet‐free SC spintronics.