Alexander I. Khachaturov

Background conductance of HTSC tunneling junctions

It is shown that some principles of the tunneling spectroscopy of conventional metals cease to be true in the case of the tunneling spectroscopy of metal oxides.

Evidence for Strong Electron-Magnon Coupling in Gadolinium

Tunneling spectroscopy measurements on normal state Gd–Gd oxide–Al junctions have been performed. Small deviations from the overall parabolic dependence of conductance on voltage were revealed and analyzed using a theoretical approach, taking into account interactions of tunneling electrons with elementary excitations in the oxide layer and metal electrodes. These processes have been studied by calculating the even and odd conductances that characterize the symmetrical (emission of oxide phonons) and asymmetrical (self-energy effects in electrodes) processes, respectively. It has been found that in gadolinium, one of the simplest magnetic metals known, an interaction of electrons with magnetic excitations is as important as the electron-phonon contribution. This result explains the difference between the calculated electron-phonon coupling parameters and the experimentally derived electron mass enhancement factors in magnetic rare-earth metals.

Electron Tunneling into a Narrow Band Conductor.

Electron tunneling between a Fermi metal and a narrow band conductor with non-quadratic E – k relationship is treated. It is shown that the tunneling characteristics of such junctions are very sens...

Manifestation of the band structure of the semimetal in the tunneling conductance of a metal–insulator–semimetal junction

The contribution of the electron band of the semimetal to the differential conductance of a metal–insulator–semimetal tunnel junction is found. It is established that the tunneling conductance depends substantially on the barrier parameters. The conductance curve exhibits a convexity with a maximum that in general does not correspond to the edges of the band or to a saddle point of the band, as has been proposed previously. It is shown that the band structure is well resolved in the second derivative of the current with respect to the voltage, d2I/dV2.