Tag

Heavy Fermion

All articles tagged with #heavy fermion

science27 days ago•21 min saved

Pressure Unveils 2D Van der Waals Heavy-Fermion Superconductivity in CeSiI

A study on CeSiI, a two‑dimensional van der Waals heavy‑fermion metal, maps its temperature–pressure phase diagram: the Kondo coherence temperature T* drops non‑monotonically with pressure to form a V shape, while antiferromagnetic order is suppressed and a superconducting dome with Tc ≈ 240 mK emerges. The superconductivity sits near magnetic instability and features a large upper critical field, suggesting unconventional pairing. Normal-state transport shows non‑Fermi‑liquid behavior and a diverging effective mass near a quantum critical point, positioning CeSiI as a platform to explore the interplay of strong correlations, Kondo hybridization, magnetism, and unconventional superconductivity in a quasi‑2D system.

via Nature|

#heavy-fermion #high-pressure #quantum-criticality

science3 months ago•71 min saved

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.

via Nature|

#dirac-revivals #flat-bands #heavy-fermion

science2 years ago•4 min saved

"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.

via SciTechDaily|

#2d-material #cesii #columbia-university