Current in a system formed by a microprobe and a thin-film layered structure

Observation of the spin-injection terahertz emission in planar ferromagnetic two-layer structures

“…As distinct from the system from [8], the rod in the structure under study is made of nonmagnetic material (copper). Such a structure corresponds to the contact ing planar ferromagnetic layers that are studied in the experiments and allows the observation of the pro cesses that are theoretically analyzed in [2][3][4]6].…”

“…The rod is used for the localization of current in the contact area and, hence, for an increase in the polar ized current density. Similarly to the systems from [8][9][10][11], the structure under study exhibits the cylindrical symmetry. Therefore, the current density decreases with increasing distance from the rod and the area of the maximum emission represents a ring around the rod whose size is approximately equal to the rod diameter.…”

“…The technological procedure for the growth of epitaxial films can be found in [12]. In gen eral, the structure under study exhibits the cylindrical symmetry and is similar to the structure from [8]. Cur rent carrying sharpened rod 4 is in contact with iron film 3.…”

“…In particular, the terahertz emission in the structure that consists of a magnetic conducting sharpened steel rod and a con tacting metal magnetic film deposited on a dielectric substrate is studied in [8][9][10][11]. A method for the cre ation of the nonequilibrium population is theoretically analyzed in [2][3][4]6], where the planar structures that consist of two ferromagnetic films are investigated in the presence of the current flow that is perpendicular to the film plane.…”

“…In this work, we study the effect related to the for mation of the nonequilibrium population (up to pop ulation inversion) of the spin energy subbands [3,6]. It is expedient to analyze the effect, since the splitting energy of the spin subbands is relatively small and the radiation frequency can be in the far IR (including terahertz) range (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). It is known that the above spectral range is poorly mastered in spite of sig nificant practical interest [7].…”