DQMP special seminar - Auditoire Stueckelberg - September 8, 2026 - 13:00 - Prof. Bernardo Barbiellini, LUT University

08.09.2026 14:00 – 15:00

Rotational Phonons Drive Low-Energy Kinks in Cuprate Superconductors
Prof. Bernardo Barbiellini
Department of Physics, LUT University

Angle-resolved photoemission spectroscopy (ARPES) reveals ubiquitous quasiparticle “kinks” near ∼70 meV and ∼40 meV across cuprate superconductors, often accompanied by peak–dip–hump (PDH) structures. These features point to strong coupling between electrons and low-energy bosonic excitations, but the microscopic origin has remained elusive due to the limitations of conventional density-functional theory (DFT) and the high cost of beyond-DFT methods. Here, we systematically study the electron–phonon coupling (EPC) in hole-doped infinite-layer CaCuO2 using the Strongly Constrained and Appropriately Normed (SCAN) density functional, explicitly including magnetic effects. We find a substantial EPC strength λ of ∼0.5 in the magnetic phase, producing kinks and PDH structures in the 40–80 meV window in excellent agreement with experiments. The dominant contribution arises from rotational oxygen phonons, while breathing modes contribute little. Our results establish strong EPC in cuprates, highlight the key role of rotational phonons, and provide a framework for understanding spectral anomalies in cuprates and beyond.

Organisé par: prof. Christoph Renner

Lieu

Bâtiment: Ecole de Physique

Auditoire Stueckelberg

entrée libre