dd2D - Unveiling transient dynamics of d-d excitations in two-dimensional antiferromagnets via time-resolved ARPES.

• Applicant: Professor Dr. Mirko Cinchetti
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 555818086

The dd2D project aims to employ multidimensional time- and angle-resolved photoelectron spectroscopy (trARPES) to explore the ultrafast dynamics of d-d excitations in the TMPS3 family, including transition metals (TM) such as Mn, Fe, Ni, and Co. These d-d excitations between localized 3d states of transition metal ions in crystalline solids, play a fundamental role in a myriad of phenomena relevant to solid-state physics, materials science, and chemistry. They contribute to the distinct coloration of transition metal oxides, are instrumental in catalytic processes on oxide surfaces, critical in high-temperature superconductivity, and drive spin-crossover transitions and optical excitation linkage to quantized collective phenomena like phonons and magnons. Historically, the field has lacked an experimental methodology capable of dissecting the intricate quasiparticle dynamics associated with d-d excitations, a gap that the dd2D project seeks to address. By focusing on the TMPS3 family of two-dimensional van der Waals antiferromagnets, dd2D intends to not only bridge this gap but also demonstrate the capabilities of our approach. This choice of materials underscores the potential inherent in d-d excitations, as recent discoveries in 2D antiferromagnets— ranging from electron-phonon bound states and sub-THz frequency magnon modes to spin-orbit entangled excitons, coherent THz optical lattice, and hybridized phonon-magnon modes—highlight the rich phenomenology stemming from d-d excitations. The project's success is expected to significantly enhance our understanding of localized d-d excitations within two-dimensional van der Waals magnets, emphasizing their essential role in manipulating magnetic order. Given the ubiquity of d-d excitations, the implications of our research are extensive. By connecting optical excitation with quantized collective phenomena like phonons and magnons, dd2D aims to unlock new research avenues across a broad spectrum of solid-state quantum systems. Although primarily grounded in fundamental physics, the project's outcomes have the potential to catalyze groundbreaking developments across various scientific and technological domains, showcasing its broader significance and application.

• DFG Programme: Research Grants
• International Connection: Spain
• Cooperation Partner: Dr. José Jaime Baldovi