Physics & Astronomy Condensed Matter Seminar
Title: Kinetic magnetism and unconventional pairing: moiré system and electron-doped cuprates
Abstract: The magnetic and superconducting properties of correlated electron systems are traditionally attributed to exchange-driven interactions stemming from Coulomb repulsion. However, recent advances suggest that kinetic mechanisms—arising purely from the motion of doped carriers in a strongly interacting background—can drive both magnetism and unconventional pairing. We explore this unifying paradigm in two distinct systems: moiré heterostructures and electron-doped cuprates. In the moiré system, spin polarons emerge below half-filling and metallic Nagaoka ferromagnetism appears above, with a pseudogap metal phase predicted at low doping and intermediate fields—characterized by a single-particle gap and doping-dependent magnetization plateau.
In electron-doped cuprates, using a combination of analytical techniques and large-scale simulations in the square-lattice Hubbard model, we uncover a robust kinetic pairing mechanism enabled by frustration in charge motion. This mechanism allows d-wave superconductivity to coexist with antiferromagnetic order, as holes effectively acquire opposite "charges" on different sublattices due to spin-singlet correlations. Together, these results highlight a common origin of magnetism and superconductivity rooted in kinetic processes, and provide a broadly applicable framework for strong coupling superconductivity in doped Mott insulator.
Date:
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Location:
CP 179
Event Series:
