Related papers: Multiorbital Effects on Antiferromagnetism in Fe P…
The structure of a superconducting vortex has been studied theoretically for a dirty antiferromagnetic superconductor (AFSC), modelling an AFSC as a doped semi-metal with s-wave superconducting pairing and antiferromagnetic (dielectric)…
Emergency of superconductivity at the instabilities of antiferromagnetism (AFM), spin/charge density waves has been widely recognized in unconventional superconductors. In copper-oxide superconductors, spin fluctuations play a predominant…
Towards understanding the multi-orbital quantum antiferromagnetism in iron pnictides, effective spin couplings and spin fluctuation induced quantum corrections to sublattice magnetization are obtained in the $(\pi,0)$ AF state of a…
Films of all-important compound hafnia (HfO2) can be prepared in an orthorhombic ferroelectric (FE) state that is ideal for applications, e.g. in memories or negative-capacitance field-effect transistors. The origin of this FE state remains…
The discovery of high-temperature superconductivity in iron pnictides raised the possibility of an unconventional superconducting mechanism in multiband materials. The observation of Fermi-surface(FS)-dependent nodeless superconducting gaps…
The Berry phase due to the spin wavefunction gives rise to the orbital ferromagnetism and anomalous Hall effect in the non-coplanar antiferromagnetic ordered state on face centered cubic (fcc) lattice once the crystal is distorted…
We examine the appearance of the experimentally-observed stripe spin-density-wave magnetic order in five different orbital models of the iron pnictide parent compounds. A restricted mean-field ansatz is used to determine the magnetic phase…
We analyze the metallic (pi,0) antiferromagnetic state of a five-orbital model for iron superconductors. We find that with increasing interactions the system does not evolve trivially from the pure itinerant to the pure localized regime.…
High-temperature (high-$T_{\rm c}$) superconductivity appears as a consequence of the carrier-doping of an undoped parent compound exhibiting antiferromagnetic order; thereby, ground-state properties of the parent compound are closely…
We theoretically study the carrier doping effect for magnetism in a stacked-kagome system $\rm{{Co}_3{Sn}_2{S}_2}$ based on an effective model and the Hartree-Fock method. We show the electron filling and temperature dependences of the…
Superconductivity (SC) with the suppression of long-range antiferromagnetic (AFM) order is observed in the parent compounds of both iron-based and cuprate superconductors. The AFM wave vectors are bicollinear ($\pi$, 0) in the parent…
Motivated by recent studies on ferroelectric-like order coexisting with metallicity, we investigate ferroelectric (FE) superconductivity in which a FE-like structural phase transition occurs in the superconducting state. We consider a…
The pressure dependence of the structural ($T_s$), antiferromagnetic ($T_m$), and superconducting ($T_c$) transition temperatures in FeSe is investigated on the basis of the 16-band $d$-$p$ model. At ambient pressure, a shallow hole pocket…
The two-orbital double-exchange model is employed for the study of the magnetic and orbital orders in ($R$MnO$_3$)$_n$/($A$MnO$_3$)$_{2n}$ ($R$: rare earths; $A$: alkaline earths) superlattices. The A-type antiferromagnetic order is…
We study whether Fermi-surface (FS) nesting can give rise to high-temperature superconductivity in iron pnictides. Starting with ab initio construction of an effective four-orbital model, we employ the fluctuation-exchange approximation to…
Neutron diffraction studies of Ba(Fe[1-x]Co[x])2As2 reveal that commensurate antiferromagnetic order gives way to incommensurate magnetic order for Co compositions between 0.056 < x < 0.06. The incommensurability has the form of a small…
Altermagnetism, featuring momentum-dependent spin splitting without net magnetization, has attracted a growing interest for spintronics. We study a Fermi Hubbard model with altermagnetic order arising from the spin-anisotropic hopping near…
We use the dynamical cluster approximation, with a quantum Monte Carlo cluster solver on clusters of up to 16 orbitals, to investigate the evolution of the Fermi surface across the magnetic order-disorder transition in the two-dimensional…
Macroscopic properties of multiferroics, the systems that show simultaneously two types of ordering, could be controlled by the external fields of different nature. We analyze the behavior of multiferroics with antiferro-(AFM) and…
Superconducting pnictides are widely found to feature spin-singlet pairing in the vicinity of an antiferromagnetic phase, for which nesting between electron and hole Fermi surfaces is crucial. LiFeAs differs from the other pnictides by (i)…