Quantum-well states in Cu/Co overlayers and sandwiches

Abstract

We report ab initio calculations of quantum-well states in Cu/Co͑001͒ and Co/Cu͑001͒ overlayers and in Co/Cu/Co͑001͒ sandwiches. Overlayer states are found which coincide well with those previously identified in photoemission and inverse photoemission experiments. In Cu/Co and at energies overlapping with the substrate continuum, minority spin resonances are clearly identifiable. However, in the majority spin channel coupling to the substrate is strong enough to effectively destroy quantum-well features. In Co/Cu/Co͑001͒ sandwiches discrete states are found at similar energies to those in overlayers of corresponding Cu thicknesses, but well defined resonance states are absent in both spin channels. There is no longer a strongly size-dependent electronic structure at the Fermi energy. We conclude care must be taken in extrapolating from the electronic structure of overlayer systems to that of other modulated structures.

Nonlinear Magneto-Optical Response from Quantum Well States in Noble Metals: Double Period and Interface Localization

“…Recently, it has been demonstrated to have at least two major advantages: an enhanced sensitivity to very narrow film interface regions [10,11] and a very large magneto-optical response [12]. Considering the recent calculations predicting a possible interface localization of the QWS-induced density o f states [13] and the enhanced k-space selectivity [14], MSHG can be expected to be a powerful tool in studying the properties o f such QWS. In addition, the three-photon nature of MSHG could give rise to new (compared with MOKE) oscillatory periods appearing as a function of the film thickness [14].…”

Magnetization Induced Second Harmonic Generation from Ultrathin Metallic Multilayers

“…Transitions with a quantum well state as intermediate state are possible as well [10]. In this case QWS below E F are probed, which are completely localized inside the Cu overlayer for the minority channel [46]. Therefore they should contribute especially strongly to the oscillation in the SH light.…”

Density-functional study of the CO adsorption on the ferromagnetic fcc Co(001) film surface

“…The cobalt fcc (0 0 1) films have apparently no counterpart among films with the hcp structure. Their electronic properties in the dependence on the film thickness has been studied extensively by experimentalist and theoreticians [9][10][11] Special magnetic properties of such films [12,13] are also of interest. Let us mention yet the investigation of ultrathin bcc Co/Cu(0 0 1) films [14].…”