Metallicity and anomalous Hall effect in epitaxially strained, atomically thin RuO 2 films
Year: 2025
Type: article
Abstract: The anomalous Hall effect (AHE), a hallmark of time-reversal symmetry breaking, has been reported in rutile RuO 2 , a debated metallic altermagnetic candidate. Previously, AHE in RuO 2 was observed only in strain-relaxed thick films under extremely high magnetic fields (~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 TiO 2 / t nm RuO 2 /TiO 2 (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 RuO 2 (110) thin films. These findings establish ultrathin RuO 2 as a platform for strain-engineered magnetism and underscore the transformative potential of epitaxial design in advancing spintronic technologies.
Authors: Seung Gyo Jeong, Seungjun Lee, Seungjun Lee, Bonnie Lin, Zhifei Yang, In Hyeok Choi, Jin Young Oh, Sehwan Song, Seung wook Lee, Seung wook Lee, Sreejith Nair, Rashmi Choudhary, Juhi Parikh, Sungkyun Park, Woo Seok Choi, Jong Seok Lee, James M. LeBeau, Tony Low, Bharat Jalan
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Awards: G1264038472, LOW-ENERGY, RADICAL-BASED APPROACHES FOR METAL OXIDES OF “STUBBORN” METALS, G1798610040, G2034809290, G2189943966, G248902062, G268393116, G273056335, G3209491411, G3329507114, G3514649387, G3930779041, G403942265, G4463214162, G5815354836, G58245830, MOLECULAR AND ATOMIC ENGINEERING OF INTERFACIAL ELECTRO-CATALYTIC ENVIRONMENTS (MARIE), G666500458, LOW-ENERGY, RADICAL-BASED APPROACHES FOR METAL OXIDES OF “STUBBORN” METALS, University of Minnesota Materials Research Science and Engineering Center
OpenAlex ID: W4411208575