High-resolution Angle-resolved Photoemission Spectroscopy Study Research Articles

Angle-resolved photoemission spectroscopy study of Fe(1 1 0) single crystal: Many-body interactions between quasi-particles at the Fermi level

A high-resolution angle-resolved photoemission spectroscopy (ARPES) study of Fe(1 1 0) single crystal was conducted to elucidate many-body interactions between quasi-particles at the Fermi level at low-temperature. Two kink structures were observed in the energy-band dispersion at the binding energies of ∼40 meV and ∼270 meV for the bulk-derived band on the majority-spin Fermi surface around the Γ point. Based on analyses of the experimentally obtained real parts of the self-energy, these kink structures are derived from electron–phonon and electron–magnon interactions.

High-resolution angle-resolved photoemission spectroscopy of iron: A study of the self-energy

A high-resolution angle-resolved photoemission spectroscopy study of an Fe (1 1 0) single crystal has been conducted to clarify the role of many-body interactions acting on the quasi-particles at the Fermi level at low temperatures. We have evaluated the real and imaginary parts of the self-energy for the bulk-derived majority-spin Fermi surface around the Γ point, and found two characteristic energy scales, at ∼40 and ∼270 meV. The former corresponds to the energy scale of the Debye temperature. As for the latter, we found that it is close to the cut-off energy of the calculated magnon density-of-states. This correspondence indicates that the energy scale is related to the magnetic excitation.

High-resolution angle-resolved photoemission study of the spin-polarized Fermi surface of Ni(1 0 0)

A high-resolution angle-resolved photoemission spectroscopy study of Ni(1 0 0) has been performed to elucidate the Fermi surfaces (FSs) in the ΓXWK plane. We observed three bulk-derived FSs around the Γ point, and two closed FSs around the X point. The observed bulk-derived FSs were explained reasonably well by a first-principles band-structure calculation with the local-density approximation.

Low-energy renormalization of the electron dispersion of high-Tcsuperconductors

High-resolution angle-resolved photoemission spectroscopy studies in cuprates have detected low-energy changes in the dispersion and absorption of quasiparticles at low temperatures, in particular, in the superconducting state. Based on a $1/N$ expansion of the $t\ensuremath{-}J$-Holstein model, which includes collective antiferromagnetic fluctuations already in leading order, we argue that the observed low-energy structures are mainly caused by phonons and not by spin fluctuations, at least, in the optimal and overdoped regime.

High-resolution electron energy loss spectroscopy and angle-resolved ultra-violet photoemission spectroscopy studies of carbon monoxide on a Cs-precovered surface

There are two molecular adsorption states of CO in the system. One is , with lower C - O frequency, and the other is , with higher C - O frequency. The latter is similar to that on a clean surface. The two states of CO are occupied sequentially during the exposure to CO. The C - O stretch frequency of both states shifts to a higher value with the exposure to CO and to a lower value with higher Cs precoverage. The electronic structure of the molecule is different from that of the molecule and is of the same character as CO in a tilted mode.