Tag

Quantum Criticality

All articles tagged with #quantum criticality

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

science7 months ago•4 min saved

Quantum-Critical Surprise: New Topological State Found in CeRu4Sn6

Researchers observed a novel topological semimetal state in CeRu4Sn6 at ultracold temperatures, a phase once deemed impossible, arising from quantum criticality that ties strong electron interactions to topology. The state was signaled by an unusual Hall effect without a magnetic field, indicating robust topological behavior with potential quantum-tech applications. The team plans to explore this state in other materials and refine the topology details. Published in Nature Physics.

via ScienceAlert|

#ceru4sn6 #condensed-matter #quantum-criticality

physics7 months ago•16 min saved

Emergent Topology Arises in Quantum-Critical CeRu4Sn6

Researchers at TU Wien report that the quantum material CeRu4Sn6 enters a quantum-critical regime at ultra-low temperatures where electrons lose their particle-like character, yet the system hosts an emergent topological semimetal state. They observed a spontaneous (anomalous) Hall effect without an external magnetic field, linking quantum fluctuations to topology and suggesting that topological properties can arise even when the conventional particle-picture fails. The work also points to a generalized, emergent view of topology and proposes focusing on quantum-critical materials to discover new topological phases.

via SciTechDaily|

#ceru4sn6 #condensed-matter-physics #emergent-topological-semimetal

science2 years ago•20 min saved

"Novel 2D Van der Waals Metal Traps Heavy Electrons"

Researchers have discovered a two-dimensional heavy fermion system in the van der Waals metal CeSiI, which exhibits intriguing quantum criticality and superconductivity. This finding opens up new possibilities for studying the behavior of heavy fermions in two dimensions and exploring the potential applications of van der Waals materials in superconducting technologies. The data supporting the study are available in the paper and its Extended Data, with additional data accessible from the corresponding authors upon request.

via Nature.com|

#heavy-fermions #quantum-criticality #science

physics3 years ago•14 min saved

Controlling Heavy Fermions with Moiré Kondo Lattice Gates.

Researchers have realized a synthetic Kondo lattice in AB-stacked MoTe2/WSe2 moiré bilayers, in which the MoTe2 layer is tuned to a Mott insulating state, supporting a triangular moiré lattice of local moments, and the WSe2 layer is doped with itinerant conduction carriers. They observed heavy fermions with a large Fermi surface below the Kondo temperature and demonstrated widely and continuously gate-tunable Kondo temperatures through either the itinerant carrier density or the Kondo interaction. This study opens the possibility of in situ access to the phase diagram of the Kondo lattice with exotic quantum criticalities in a single device based on semiconductor moiré materials.

via Nature.com|

#gate-tunable #heavy-fermions #kondo-lattice