Related papers: Topological Ultranodal pair states in iron-based s…
The multipocket Fermi surfaces of iron-based superconductors promote pairing states with both s_{+-}-wave and d_{x^2-y^2}-wave symmetry. We argue that the competition between these two order parameters could lead to a time-reversal-symmetry…
We argue that a superconducting state with a Fermi-surface of Bogoliubov quasiparticles, a Bogoliubov Fermi-surface (BG-FS), can be identified by the dependence of physical quantities on disorder. In particular, we show that a linear…
Nodal noncentrosymmetric superconductors have topologically nontrivial properties manifested by protected zero-energy surface states. Specifically, it was recently found that zero-energy surface flat bands of topological origin appear at…
In iron-based superconductors, band inversion of $d$- and $p$-orbitals yields Dirac semimetallic states. We theoretically investigate their topological properties in normal and superconducting phases, based on the tight-binding model…
Iron-chalcogenide superconductors FeSe$_{1-x}$S$_x$ possess unique electronic properties such as non-magnetic nematic order and its quantum critical point. The nature of superconductivity with such nematicity is important for understanding…
We systematically study gapless topological phases of (semi-)metals and nodal superconductors described by Bloch and Bogoliubov-de Gennes Hamiltonians. Using K-theory, a classification of topologically stable Fermi surfaces in (semi-)metals…
Realization of topological superconductors is one of the most important goals in studies of topological phases in quantum materials. In this work, we theoretically propose a novel way to attain topological superconductors with non-trivial…
On the basis of a scenario where electron pairing is induced by resonant two-particle scattering (the Boson Fermion model), we show how precursors of the superconducting state - in form of overdamped Bogoliubov modes - emerge in the normal…
S-substituted FeSe superconductors in the tetragonal phase display several unique features among iron-based superconductors, particularly the presence of zero-energy excitations in the superconducting (SC) state. The recent concept of…
Three-dimensional line-nodal superconductors exhibit nontrivial topology, which is protected by the time-reversal symmetry. Here we investigate four types of short-range interaction between the gapless line-nodal fermionic quasiparticles by…
In the past few years materials with protected gapless surface (edge) states have risen to the central stage of condensed matter physics. Almost all discussions centered around topological insulators and superconductors, which possess full…
We study theoretically the thermoelectric effect in a superconducting state having the Bogoliubov-Fermi surfaces which stays in a thin superconducting layer between a conventional superconductor and an insulator. The thermoelectric…
We present an analytical study of the ground-state phase diagram for dilute two-dimensional spin-1/2 Fermi gases exhibiting $d$-wave altermagnetic spin splitting under $s$-wave pairing. Within the Bogoliubov-de Gennes mean-field framework,…
Superconductors with an odd number of bands crossing the Fermi energy have topologically protected Andreev states at interfaces, including Majorana states in one dimensional geometries. Superconductivity, a low number of 1D channels, large…
We investigate theoretically the properties of s-wave multiband superconductors in the weak coupling (BCS) limit in the presence of pair-breaking effects of magnetic field. It is shown that a qualitatively new gapless superconducting state…
Topological insulators and semimetals as well as unconventional iron-based superconductors have attracted major recent attention in condensed matter physics. Previously, however, little overlap has been identified between these two vibrant…
We consider a non-Hermitian superconducting system by coupling a conventional superconductor to a ferromagnet lead and demonstrate the emergence of exceptional points when an external Zeeman field is applied. We discover that, depending on…
We study the superconducting state in the presence of spin-orbital coupling and the Zeeman field. It is found that a phase transition from the Fulde-Ferrell-Larkin-Ovchinnikov state to the topological superconducting state occurs upon…
Topological nodal superconductors are generally realized based on unconventional pairings. In this work, we propose a minimal model to realize these topological nodal phases with only $s$-wave interaction. In our model the linear and…
We investigate the impact of s-wave spin-singlet pairing on antiferromagnetic semimetals with Dirac points or nodal loops at the Fermi level. The electron pairing is generally shown to convert the semimetal into a tunable nodal…