Tag

Heavy Fermion

All articles tagged with #heavy fermion

Direct imaging uncovers dual light and heavy electron bands in magic-angle graphene
science20 days ago

Direct imaging uncovers dual light and heavy electron bands in magic-angle graphene

Using the quantum twisting microscope, researchers map the interacting energy bands of magic-angle twisted bilayer graphene (MATBG). Away from the magic angle the bands follow single-particle predictions, but at the magic angle interactions reshape them into largely flat, gapped bands across most of momentum space, with dispersive, light-electron states near Γ. Upon doping, charge transfers between light (c-like) and heavy (f-like) states drive bandwidth renormalization, Mott-like cascades, and Dirac revivals, while an unexplained ~15 meV excitation hints at an additional degree of freedom. The work resolves MATBG’s long-standing duality and showcases the quantum twisting microscope as a powerful tool for high-resolution quantum-material spectroscopy.

"Novel Quantum Material: Layered Metal Traps 1000x Heavier Electrons in Two Dimensions"
science2 years ago

"Novel Quantum Material: Layered Metal Traps 1000x Heavier Electrons in Two Dimensions"

Columbia University researchers have synthesized the first 2D heavy fermion material, CeSiI, a breakthrough in quantum material science that paves the way for new research into quantum phenomena and the design of innovative materials. This material, with electrons up to 1000 times heavier than usual, offers new possibilities in understanding quantum phenomena, including superconductivity, and is easier to manipulate and combine with other materials due to its 2D structure. The development opens up new avenues for exploring fundamental physics and probing unique quantum phases, with potential applications in the design of new materials.