Related papers: Coexisting Itinerant and Localized Electrons in Ir…
We present a unified theory of magnetism and superconductivity of $UGe_2$. To this end, we consider part of $5f$ uranium electrons as mostly itinerant and other ones as mostly localized. The main feature that distinguishes the localized…
Motivated by the iron-based superconductors, we develop a self-consistent electronic theory for the itinerant spin excitations in the regime of coexistence of the antiferromagnetic stripe order with wavevector ${\bf Q}_{1} = (\pi,0)$ and…
Nine years ago, superconductors based on the magnetic element iron were discovered. A flurry of research activity has revealed an unprecedented diversity of chemical structures and physical properties. Similarly to other unconventional…
While superconductors are conventionally established by attractive interactions, higher-temperature mechanisms for emergent electronic pairing from strong repulsive electron-electron interactions remain under considerable scrutiny. Here, we…
Electron-electron interactions are at the origin of many exotic electronic properties of materials which have emerged from recent experimental observations. The main important phenomena discovered are related with electronic magnetic…
In the weak regime, we suggest a model where superconductivity types I and II bind assuming an adiabatic hypothesis where the frequency of oscillation of free electrons is much smaller than of polarons coupled to phonons, and an itinerant…
Correlated electron systems are among the centerpieces of modern condensed matter sciences, where many interesting physical phenomena, such as metal-insulator transition and high-Tc superconductivity appear. Recent efforts have been focused…
Although iron-based superconductors are multi-orbital systems with complicated band structures, we demonstrate that the low energy physics which is responsible for high-$T_c$ superconductivity is essentially governed by one effective…
We construct a mean-field theory for itinerant ferromagnetism coexisting with a non-unitary superconducting state, where only the majority-spin band is gapped and contains line nodes, while the minority-spin band is gapless at the Fermi…
We present a simple, general energy functional for ferromagnetic materials based upon a local spin density extension to the Stoner theory of itinerant ferromagnetism. The functional reproduces well available ab initio results and…
Electrons in condensed matter may transition into a variety of broken-symmetry phase states due to electron-electron interactions. Applying diverse mean-field approximations to the interaction term is arguably the simplest way to identify…
The intimate connection between magnetism and superconducting pairing routinely plays a central role in determining the occurrence of unconventional superconducting states. In high-transition-temperature (high-Tc) stripe-ordered cuprate…
We examine the relevance of magneto-elastic coupling to describe the complex magnetic and structural behaviour of the different classes of the iron superconductors. We model the system as a two-dimensional metal whose magnetic excitations…
The symmetry properties and the general overview of the superconductivity theory in the itinerant ferromagnets and in materials without space parity are presented. The basic notions of unconventional superconductivity are introduced in…
Superconductivity in the iron pnictides and chalcogenides is closely connected to a bad-metal normal state and a nearby antiferromagnetic order. Therefore, considerable attention has been focused on the role of electron correlations and…
On the basis of a two-dimensional t-t' Hubbard model in ferromagnetic and paramagnetic states, the triplet superconducting mechanism is investigated by the third-order perturbation theory with respect to the on-site Coulomb interaction U.…
Electrides are materials with electrons localized at interstitial regions of the crystal lattice and have been identified as promising candidates for a variety of applications, including catalysis, electron emission, and superconductivity.…
Ferromagnetic superconductors, where ferromagnetism and superconductivity coexist despite their antagonism, exhibit strikingly diverse behaviors. Depending on the interplay between the ferromagnetic exchange field and the superconducting…
Unconventional superconductivity (SC) is said to occur when Cooper pair formation is dominated by repulsive electron-electron interactions, so that the symmetry of the pair wavefunction is other than isotropic s-wave. The strong, on-site,…
The electronic structure and magnetism of LiFeO$_{2}$Fe$_{2}$Se$_{2}$ are investigated using the first-principle calculations. The ground state is N$\acute{e}$el antiferromagnetic (AFM) Mott insulating state for Fe1 with localized magnetism…