Metallicity and anomalous Hall effect in epitaxially strained, atomically thin RuO2 films
成果类型：
Article
署名作者：
Jeong, Seung Gyo; Lee, Seungjun; Lin, Bonnie; Yang, Zhifei; Choi, In Hyeok; Oh, Jin Young; Song, Sehwan; Lee, Seung wook; Nair, Sreejith; Choudhary, Rashmi; Parikh, Juhi; Park, Sungkyun; Choi, Woo Seok; Lee, Jong Seok; Lebeau, James M.; Low, Tony; Jalan, Bharat
署名单位：
University of Minnesota System; University of Minnesota Twin Cities; University of Minnesota System; University of Minnesota Twin Cities; Massachusetts Institute of Technology (MIT); University of Minnesota System; University of Minnesota Twin Cities; Gwangju Institute of Science & Technology (GIST); Sungkyunkwan University (SKKU); Pusan National University
刊物名称：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN/ISSBN：
0027-11949
DOI：
10.1073/pnas.2500831122
发表日期：
2025-06-17
关键词：
diffraction
TRANSITION
thickness
SPECTRA
state
摘要：
The anomalous Hall effect (AHE), a hallmark of time-reversal symmetry breaking, has been reported in rutile RuO2, a debated metallic altermagnetic candidate. Previously, AHE in RuO2 was observed only in strain-relaxed thick films under extremely high magnetic fields (similar to 50 T). Yet, in ultrathin strained films with distinctive anisotropic electronic structures, there are no reports, likely due to disorder and defects suppressing metallicity thus hindering its detection. Here, we demonstrate that ultrathin, fully strained 2 nm TiO2/t nm RuO2/TiO2 (110) heterostructures, grown by hybrid molecular beam epitaxy, retain metallicity and exhibit a sizeable AHE at a significantly lower magnetic field (< 9 T). Density functional theory calculations reveal that epitaxial strain stabilizes a noncompensated magnetic ground state and reconfigures magnetic ordering in RuO2 (110) thin films. These findings establish ultrathin RuO2 as a platform for strain-engineered magnetism and underscore the transformative potential of epitaxial design in advancing spintronic technologies.