Jung, Hyeonjung So, Gimok Noh, Seunghyeon Kim, Gye-Hyeon Lee, Jiyeon Lee, Jaebyeong Lee, Seunghyun Seo, Uihyeon Han, Dong-Soo Oh, Yoon Seok Jin, Hosub Sohn, Changhee Yoo, Jung-Woo 2025-12-03T02:01:03Z 2025-12-03T02:01:03Z 2025-11-28 2025-12 1530-6984 https://pubs.kist.re.kr/handle/201004/153735 Spin-dependent anisotropic Fermi surfaces in altermagnets can give rise to nonrelativistic spin–charge conversion, known as the altermagnetic spin splitting effect (ASSE). While several studies have reported the inverse ASSE (IASSE) in altermagnetic RuO2 thin films, its magnitude and sign relative to the spin Hall effect (SHE) remain controversial. Here, we demonstrate reversible IASSE in RuO2 thin films by controlling the Néel vector orientation and accounting for the anisotropic transport characteristic. Spin Seebeck measurements in CoFeB/RuO2 heterostructures reveal polarity reversal of the IASSE-induced spin charge conversion (SCC) upon Néel vector switching. This indicates that IASSE can either enhance or suppress SCC depending on the Néel orientation. These results provide compelling evidence for the symmetry-governed and directionally reversible nature of IASSE in RuO2. English American Chemical Society Reversible Spin Splitting Effect in Altermagnetic RuO2 Thin Films Article 10.1021/acs.nanolett.5c03644 1 Nano Letters, v.25, no.49, pp.16985 - 16991 Nano Letters 25 49 16985 16991 N scie scopus 001623176000001 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article altermagnet altermagnetic spin splitting effect spin Hall effect Neel vector spinSeebeck effect