Colossal magnetoresistance from spin-polarized polarons in an Ising system

• 成果类型: Article
• 署名作者: Li, Ying-Fei; Been, Emily M.; Balguri, Sudhaman; Jia, Chun-Jing; Mahendru, Mira B.; Wang, Zhi-Cheng; Cui, Yi; Chen, Su-Di; Hashimoto, Makoto; Lu, Dong-Hui; Moritz, Brian; Zaanen, Jan; Tafti, Fazel; Devereaux, Thomas P.; Shen, Zhi-Xun
• 署名单位: Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; Stanford University; Stanford University; Boston College; State University System of Florida; University of Florida; University of California System; University of California Berkeley; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; Leiden University - Excl LUMC; Leiden University; Stanford University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10401
• DOI: 10.1073/pnas.2409846121
• 发表日期: 2024-12-10
• 关键词: initio molecular-dynamics; total-energy calculations; ultrahigh mobility; TRANSITION

摘要

Recent experiments suggest a new paradigm toward novel colossal magnetoresistance (CMR) in a family of materials EuM2X2 (M = Cd, In, Zn; X = P, As), distinct from the traditional avenues involving Kondo-Ruderman-Kittel-Kasuya-Yosida crossovers, magnetic phase transitions with structural distortions, or topological phase transitions. Here, we use angle-resolved photoemission spectroscopy and density functional theory calculations to explore their origin, particularly focusing on EuCd2P2. While the low- energy spectral weight royally tracks that of the resistivity anomaly near the temperature with maximum magnetoresistance (TMR) as expected from transport-spectroscopy correspondence, the spectra are completely incoherent and strongly suppressed with no hint of a Landau quasiparticle. Using systematic material and temperature dependence investigation complemented by theory, we attribute this nonquasiparticle caricature to the strong presence of entangled magnetic and lattice interactions, a characteristic enabled by the p-f mixing. Given the known presence of ferromagnetic clusters, this naturally points to the origin of CMR being the scattering of spin-polarized polarons at the boundaries of ferromagnetic clusters. These results are not only illuminating to investigate the strong correlations and topology in EuCd2X2 family, but, in a broader view, exemplify how multiple cooperative interactions can give rise to extraordinary behaviors in condensed matter systems.