Orbital-differentiated coherence-incoherence crossover identified by photoemission spectroscopy in LiFeAs

Abstract

In the iron-based superconductors (FeSCs), orbital differentiation is an important phenomenon, whereby correlations stronger on the dxy orbital than on the dxz/yz orbital yield quasi-particles with dxy} orbital character having larger mass renormalization and abnormal temperature evolution. However, the physical origin of this orbital differentiation is debated between the Hund's coupling induced unbinding of spin and orbital degrees of freedom and the Hubbard interaction instigated orbital selective Mott transition. Here we use angle-resolved photoemission spectroscopy to identify an orbital-dependent correlation-induced quasi-particle (QP) anomaly in LiFeAs. The excellent agreement between our photoemission measurements and first-principles many-body theory calculations shows that the orbital-differentiated QP lifetime anomalies in LiFeAs are controlled by the Hund's coupling.

References in corpus (8)

• Magnetism and Charge Dynamics in Iron Pnictides
• The coherence-incoherence crossover and the mass-renormalization puzzles in Sr2RuO4
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A${}_x$Fe${}_{2-y}$Se${}_2$ (A=K, Rb) Superconductors
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• Observation of an Orbital Selective Electron-Mode Coupling in Fe-Based High-$T_c$ Superconductors
• Observation of strong electron pairing on bands without Fermi surfaces in LiFe1-xCoxAs
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Cited by in corpus (3)

• Orbital-selective Mott phase in multiorbital models for iron pnictides and chalcogenides
• Analytical slave-spin mean-field approach to orbital selective Mott insulators
• Observation of an Emergent Coherent State in the Iron-Based Superconductor KFe${}_2$As${}_2$