C. S. Leem

Novel Jeff=1/2 Mott state induced by relativistic spin-orbit coupling in Sr2IrO4.

We investigated the electronic structure of 5d transition-metal oxide Sr2IrO4 using angle-resolved photoemission, optical conductivity, x-ray absorption measurements, and first-principles band calculations. The system was found to be well described by novel effective total angular momentum Jeff states, in which the relativistic spin-orbit coupling is fully taken into account under a large crystal field. Despite delocalized Ir 5d states, the Jeff states form such narrow bands that even a small correlation energy leads to the Jeff=1/2 Mott ground state with unique electronic and magnetic behaviors, suggesting a new class of Jeff quantum spin driven correlated-electron phenomena.

Electronic structure of electron-doped Sm 1.86 Ce 0.14 Cu O 4 : Strong pseudogap effects, nodeless gap, and signatures of short-range order

Angle-resolved photoemission spectroscopy (ARPES) data from the electron-doped cuprate superconductor

Effect of linear density of states on the quasiparticle dynamics and small electron-phonon coupling in graphite.

{\mathrm{Sm}}_{1.86}{\mathrm{Ce}}_{0.14}\mathrm{Cu}{\mathrm{O}}_{4}

Angle-resolved photoemission spectroscopy of electron-doped cuprate superconductors: isotropic electron-phonon coupling.

show a much stronger pseudogap or hot-spot effect than that observed in other optimally doped

High-resolution angle-resolved photoemission studies of quasiparticle dynamics in graphite

n

Electron removal self-energy and its application to Ca 2 Cu O 2 Cl 2

-type cuprates. Importantly, these effects are strong enough to drive the zone-diagonal states below the chemical potential, implying that

Oxygen-content-dependent electronic structures of electron-doped cuprates

d

Photoemission studies of Cu intercalated NbSe2

-wave superconductivity in this compound would be of the nodeless gap variety. The gross features of the Fermi surface topology and low-energy electronic structure are found to be well described by reconstruction of bands by a

Imaging the electron density in solids by using multi-Brillouin-zone angle resolved photoelectron spectroscopy

\sqrt{2}\ifmmode\times\else\texttimes\fi{}\sqrt{2}

Self-energy analysis of multiple-bosonic mode coupling in Sr2RuO4

order. Comparison of the ARPES and optical data from the same sample shows that the pseudogap energy observed in optical data is consistent with the interband transition energy of the model, allowing us to have a unified picture of pseudogap effects. However, the high-energy electronic structure is found to be inconsistent with such a scenario. We show that a number of these model inconsistencies can be resolved by considering a short-range ordering or inhomogeneous state.