相关论文: Nematicity driven by hybridization in iron-based s…
The underdoped phase diagram of the iron-based superconductors exemplifies the complexity common to many correlated materials. Indeed, multiple ordered states that break different symmetries but display comparable transition temperatures…
Studies of the copper-based superconductors demonstrate how their phase diagram becomes more complex as experimental probes improve, able to distinguish among subtly different electronic phases. One of those phases, nematicity, has become…
We investigate unconventional superconductivity in three-dimensional electronic systems with the chemical potential close to a quadratic band touching point in the band dispersion. Short-range interactions can lead to d-wave…
The main features in iron-based superconductors would be (i) the orthorhombic transition accompanied by remarkable softening of shear modulus, (ii) high-Tc superconductivity close to the orthorhombic phase, and (iii) nematic transition in…
Electronic nematicity, a correlated state that spontaneously breaks rotational symmetry, is observed in several layered quantum materials. In contrast to their liquid-crystal counterparts, the nematic director cannot usually point in an…
The emergence of nematic electronic states accompanied by a structural phase transition is a recurring theme in many correlated electron materials, including the high-temperature copper oxide- and iron-based superconductors. We provide…
Nematic order in the iron-based superconductors is closely tied to a lattice distortion and a structural transition from tetragonal to orthorhombic symmetry. External stress of the appropriate symmetry acts as a conjugate field of the…
A theory of superconductivity in the iron-based materials requires an understanding of the phase diagram of the normal state. In these compounds, superconductivity emerges when stripe spin density wave (SDW) order is suppressed by doping,…
Electronic nematicity plays important role in iron-based superconductors. These materials have layered structure and theoretical description of their magnetic and nematic transitions has been well established in two-dimensional…
In this work, we study a biquadratic Heisenberg model with coupled orbital degree of freedom using Monte Carlo simulation in order to investigate the phase transitions in iron-based superconductors. The antiferro-quadrupolar state, which…
Spin-driven nematicity, or the breaking of the point-group symmetry of the lattice without long-range magnetic order, is clearly quite important in iron-based superconductors. From a symmetry point of view, nematic order can be described as…
I review works on Fe-based superconductors which depart from a metal with well defined Fermi surfaces and Fermi liquid-type quasiparticles. I consider normal state instabilities -- SDW magnetism and nematic order, and superconductivity, all…
We study the interplay of nematic and superconducting order in the two-dimensional Hubbard model and show that they can coexist, especially when superconductivity is not the energetically dominant phase. Due to a breaking of the $C_4$…
Elucidating the microscopic origin of nematic order in iron-based superconducting materials is important because the interactions that drive nematic order may also mediate the Cooper pairing. Nematic order breaks fourfold rotational…
The theoretical understanding of the nematic state of iron-based superconductors and especially of FeSe is still a puzzling problem. Although a number of experiments calls for a prominent role of local correlations and place iron…
At low temperatures, some lattice spin models with simple ferromagnetic or antiferromagnetic interactions (for example nearest-neighbour interaction being isotropic in spin space on a bipartite three-dimensional lattice) produce…
We show that the fluctuations associated with ferro orbital order in the $d_{xz}$ and $d_{yz}$ orbitals can develop a sharp resonance mode in the superconducting state with a nodeless gap on the Fermi surface. This orbital resonance mode…
A system that possesses translational symmetry but breaks orientational symmetry is known as a nematic phase. While there are many examples of nematic phases in a wide range of contexts, such as in liquid crystals, complex oxides, and…
We study superconducting instability from orbital nematic fluctuations in a minimal model consisting of the $d_{xz}$ and $d_{yz}$ orbitals, and choose model parameters which capture the typical Fermi surface geometry observed in iron-based…
The origin of spontaneous electronic nematic ordering provides important information for understanding iron-based superconductors. Here, we analyze a scenario where the $d_{xy}$ orbital strongly contributes to nematic ordering in FeSe. We…