LiV_(2)O_(4)is a spinel-structured compound that stands out as the first known 3d-electron system exhibiting typical heavy fermion behavior.A central question is how such strong mass renormalization emerges in the abs...LiV_(2)O_(4)is a spinel-structured compound that stands out as the first known 3d-electron system exhibiting typical heavy fermion behavior.A central question is how such strong mass renormalization emerges in the absence of f-electrons.In this work,we investigate the three-dimensional electronic structure of LiV_(2)O_(4)thin films using angle-resolved photoemission spectroscopy.We identify that an electron-like flat band is derived from a_(1g)orbitals,along with a highly dispersive e′_(g)band strongly coupled with phonons.The overall agreement with dynamical mean-field theory calculations highlights the essential role of inter-orbital Hund’s coupling in reducing the a_(1g)bandwidth to 25 meV,approaching a Mott state.Notably,we find that heavy-fermion behavior arises from additional renormalization at the a_(1g)band near the Fermi level,likely driven by many-body interactions at energy scales down to a few meV and potentially linked to geometric frustration inherent to the spinel lattice.These results provide crucial insights into the origin of the heavy fermion behavior in 3d-electron systems.展开更多
基金support of Dr.Z.T.Liu,Dr.Z.C.Jiang,Dr.Marta Zonno,and Dr.Sergey Gorovikovsupported in part by the National Key R&D Program of the MOST of China(Grant No.2023YFA1406300)+4 种基金the National Natural Science Foundation of China(Grant Nos.12274085,12422404,and 92477206)the New Cornerstone Science Foundation,the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302803)Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)The ARPES measurements used Beamlines 09U and 03U of the SSRF and Beamline QMSC of Canadian Light sourcesupported by the ME2 project from the National Natural Science Foundation of China(Contract No.11227902).
文摘LiV_(2)O_(4)is a spinel-structured compound that stands out as the first known 3d-electron system exhibiting typical heavy fermion behavior.A central question is how such strong mass renormalization emerges in the absence of f-electrons.In this work,we investigate the three-dimensional electronic structure of LiV_(2)O_(4)thin films using angle-resolved photoemission spectroscopy.We identify that an electron-like flat band is derived from a_(1g)orbitals,along with a highly dispersive e′_(g)band strongly coupled with phonons.The overall agreement with dynamical mean-field theory calculations highlights the essential role of inter-orbital Hund’s coupling in reducing the a_(1g)bandwidth to 25 meV,approaching a Mott state.Notably,we find that heavy-fermion behavior arises from additional renormalization at the a_(1g)band near the Fermi level,likely driven by many-body interactions at energy scales down to a few meV and potentially linked to geometric frustration inherent to the spinel lattice.These results provide crucial insights into the origin of the heavy fermion behavior in 3d-electron systems.
