Isotropic Kink and Quasiparticle Excitations in the Three-Dimensional Perovskite ManganiteLa0.6Sr0.4MnO3

Abstract

In order to reveal many-body interactions in the three-dimensional (3D) perovskite manganite, we have performed an in situ angle-resolved photoemission spectroscopy (ARPES) on La 0.6 Sr 0.4 MnO 3 (LSMO) and investigated the behaviors of quasiparticles. We observe quasiparticle peaks around the Fermi momentum, both in the electron and the hole bands, and clear kinks throughout the hole Fermi surface in the ARPES band dispersion. The isotropic behavior sharply contrasts to the strong anisotropic quasiparticle excitation observed in layered manganites.These results suggest that polaronic quasiparticles by coupling of the electrons with Jahn-Teller phonons play an important role in the physical properties of the ferromagnetic metallic phase in 3D manganite LSMO.

Spin-dependent and spin-independent channels of electrical transport in perovskite manganites

“…where k B is the Boltzmann constant. The parameters in eqn (2) were determined by tting the experimental curves of r versus T, and the results are listed in Table 2. For example, the parameters for the sample with x ¼ 0.20 were determined as follows: rst, it can be seen that the curve of r versus (T 1 + T) 3 can be approximated as a straight line at lower temperatures by adjusting the parameter T 1 , as shown in Fig.…”

“…must substitute for r 1 in eqn (2). The values of the tted parameters a 11 , E 1 , a 2 , E 2 , a 3 , and E 3 are listed in Table 2.…”

“…As shown in eqn (2) and Tables 2 and 3, the spin-dependent resistivities, r 1 and r 2 , are represented by parameters (or regression coefficients) that play interesting roles:…”

“…There have been many investigations on the electronic transport and magnetic properties of perovskite oxides [1][2][3][4][5][6][7][8][9][10][11][12] because of their potential application in both electronic and magnetic information-storage devices. There are several models for the electronic-transport properties of these materials, and spindependent transport has been taken into account by most researchers.…”

“…One of the popular views is that there is polaron hopping below the Curie temperature (T C ) on the basis of the double-exchange interaction. 2,3,13 In this view, the current carriers of perovskite manganites originate from the d electrons of manganese cations. Another view was proposed by Alexandrov et al, 13,14 who argued that the current carriers of perovskite manganites originate from the p holes of oxygen anions rather than the d electrons of manganese cations, based on the experimental results of electron-energy-loss spectroscopy 15,16 and X-ray absorption spectroscopy.…”