Related papers: Analysis of long range order
We discuss a simple phenomenological Landau theory of phase transitions with two coupled single-component order parameters and compare the results with available experimental data. The model corresponds to the case of a ferroic system, in…
We investigate the effect of alloying at the 3d transition metal site of a rare-earth-transition metal oxide, by considering NdFe0.5Cr0.5O3 alloy with two equal and random distribution of 3d ions, Cr and Fe, interacting with an early 4f…
The competition between long-range and short-range interactions among holes moving in an antiferromagnet (AF), is studied within a model derived from the spin density wave picture of layered transition metal oxides. A novel numerical…
We report temperature-dependent Raman scattering and X-ray diffraction studies of pyrochlore iridates, (Eu$_{1-x}$Bi$_x$)$_2$Ir$_2$O$_7$, for x=0, 0.02, 0.035, 0.05 and 0.1. The temperature variation in Raman experiments spans from 4 K to…
In an electron system coupled with anharmonic phonons, i.e., {\it rattling}, inverse isotope effect on the Kondo temperature $T_{\rm K}$ is found to occur by the numerical evaluation of the Sommerfeld constant $\gamma$ of the…
We address and resolve the fundamental contradiction that has existed from the earliest studies on magnetic phase transitions between theoretical models that ignore the role of thermal vibrations and represent the exchange interaction as a…
Using low-energy electron diffraction, we show that the room-temperature $(\sqrt{2}\times\sqrt{2})R45^\circ$ reconstruction of Fe$_3$O$_4$(100) reversibly disorders at $\sim$450 $^\circ$C. Short-range order persists above the transition,…
We use the renormalization group method to examine the effect of phonon mediated interaction on d-wave superconductivity, as driven by spin fluctuations in a quasi-one-dimensional electron system. The influence of a tight-binding…
We suggest universal expressions for the rates of charge transition between molecules in organic disordered semiconductors, which differ between electrons and holes. The donor and acceptor molecules (monomers) are represented in terms of…
Rutile TiO2 is a paradigmatic transition metal oxide with applications in optics, electronics, photocatalysis, etc., that are subject to pervasive electron-phonon interaction. To understand how energies of its electronic bands, and in…
We discuss the role of dynamical many-electron effects in the physics of iron and iron-rich solid alloys under applied pressure on the basis of recent ab initio studies employing the dynamical mean-field theory (DMFT). Electronic…
The technological performances of metallic compounds are largely influenced by atomic ordering. Although there is a general consensus that successful theories of metallic systems should account for the quantum nature of the electronic glue,…
We study the nonequilibrium dynamics of photoinduced phase transitions in charge ordered (CO) systems with a strong electron-lattice interaction and analyze the interplay between electrons, periodic lattice distortions, and a phonon thermal…
By combining {\it ab initio} results for the electronic structure and phonon spectrum with the group theory, we establish the origin of the Verwey transition in Fe$_3$O$_4$. Two primary order parameters with $X_3$ and $\Delta_5$ symmetries…
Motivated by the considerable importance of material properties in modern condensed matter physics research, and using techniques of the $N_{e}$ -electron systems in terms of the electron density $n_{\sigma e}\left( r\right) $ needed to…
The unavoidable presence of vibrations in solid-state devices can drastically modify the expected electron spin resonance (ESR) absorption spectrum in magnetically active systems. In this work, we model the effect of phonons and temperature…
The interaction of many-body systems with intense light pulses may lead to novel emergent phenomena far from equilibrium. Recent discoveries, such as the optical enhancement of the critical temperature in certain superconductors and the…
To sum up, we show in the present paper that magnetic response in Nb$_2$O$_2$F$_3$ at the high-temperatures ($T>$90 K) is related to the orbital selective regime, when part of the electrons form molecular orbitals while other electrons have…
The complex atomic scale structure of high entropy alloys presents new opportunities to expand the deformation theories of mechanical metallurgy. In this regard, solute-defect interactions have emerged as critical piece in elucidating the…
The effects of thermal diffuse scattering on the transmission and eventual diffraction of highly accelerated electrons are investigated with a method that incorporates the frozen phonon approximation to the exact numerical solution of the…