Related papers: Analysis of long range order
All theoretical models (Heisenberg, Ising etc.) assume a negligible role for thermal vibrations in alloy and magnetic phase transitions. Analysis of diffraction data conclusively proves that this assumption is incorrect. A simple criterion…
Electron-ion interactions play a central role for the energy relaxation processes and ultra-fast structure dynamics in laser-heated matter. The accurate prediction of the electron-ion energy exchange in a transient excited two-temperature…
The rate of energy transfer between electrons and phonons is investigated by a first principles framework for electron temperatures up to $T_e=50000$ K while considering the lattice at ground state. Two typical but differently complex…
Looking for superconductors with higher transition temperature requires a guiding principle. In conventional superconductors, electrons pair up into Cooper pairs via the retarded attraction mediated by electron-phonon coupling.…
Temperature dependence of longitudinal optical phonons with oxygen character was measured in La1-xSrxMnO3 (x=0.2, 0.3) by inelastic neutron scattering in the (1 0 0) cubic direction. The zone center mode intensity is consistent with the…
TThe isotope effect is a powerful probe of electron-phonon interactions in solid-state systems, offering key insights into how atomic mass influences emergent quantum states. Here, the impact of oxygen isotope substitution ($^{16}{\rm…
The theory of Raman scattering in half-metals by optical phonons interacting with conduction electrons is developed. We evaluate the effect of electron-phonon interactions at ferromagnetic ordering in terms of the Boltzmann equation for…
We present a theory for the rate of energy exchange between electrons and ions -- also known as the electron-ion coupling factor -- in physical systems ranging from hot solid metals to plasmas, including liquid metals and warm dense matter.…
We report a Raman study of the effect of temperature on the self-energies of optical phonons in a number of transition metals with hexagonal-close-packed structure. Anisotropic softening of phonon energies and narrowing of phonon linewidths…
It is shown that in all types of metallic magnets the coupling of the order parameter to the conduction electrons leads to an order-parameter susceptibility that is long-ranged at zero temperature. This is true for all known classes of…
Recent studies of pairing and charge order in materials such as FeSe, SrTiO$_3$, and 2H-NbSe$_2$ have suggested that momentum dependence of the electron-phonon coupling plays an important role in their properties. Initial attempts to study…
Hexagonal YMnO$_3$ is well known for the co-occurrence of ferroelectricity and antiferromagnetism at low temperatures. Using temperature-dependent spectroscopic ellipsometry at an $a$-plane oriented single crystal, we show how the…
Effects of electron-phonon interactions on the band structure can be experimentally investigated in detail by measuring the temperature dependence of energy gaps or critical points (van Hove singularities) of the optical excitation spectra.…
Phase transitions occur when a macroscopic number of local degrees of freedom coherently change their behavior. In ground states of quantum many-body systems, phase transitions due to quantum fluctuations are observed as non-analytic…
Energy transfer from electrons to phonons is an important consideration in any Weyl or Dirac semimetal based application. In this work, we analytically calculate the cooling power of acoustic phonons, i.e. the energy relaxation rate of…
We report a molecular dynamics study of ab initio quality of the ferroelectric phase transition in crystalline PbTiO3. We model anharmonicity accurately in terms of potential energy and polarization surfaces trained on density functional…
The low temperature transport of electron, or vibrational or electronic exciton towards polymer chains turns out to be dramatically sensitive to its interaction with transverse acoustic vibrations. We show that this interaction leads to…
We investigate three dimensional anharmonic phonons in tetrahedral symmetry and superconductivity mediated by these phonons. Three dimensional anharmonic phonon spectra are calculated directly by solving Schr\"odinger equation and the…
We have developed a methodology to study the thermodynamics of order-disorder transformations in n-component substitutional alloys that combines nonequilibrium methods, which can efficiently compute free energies, with Monte Carlo…
Electron-phonon coupling is a fundamental process that governs the energy relaxation dynamics of solids excited by ultrafast laser pulses. It has been found to strongly depend on electron temperature as well as on nonequilibrium effects.…