Related papers: Fermiology with nodal structures in nonsymmorphic …
We report electronic structure calculations for the layered centrosymmetric superconductor LaNiGa$_2$, which has been identified as having a possible triplet state based on evidence for time reversal symmetry breaking. The Fermi surface has…
LaNiGa$_2$ is superconductor that breaks time-reversal symmetry in the superconducting state without any known nearby magnetism. Recently, single crystals of LaNiGa$_2$ have been synthesized, revealing a nonsymmorphic Cmcm space group.…
Unconventional superconductors have Cooper pairs with lower symmetries than in conventional superconductors. In most unconventional superconductors, the additional symmetry breaking occurs in relation to typical ingredients such as strongly…
Locally noncentrosymmetric structures in crystals are attracting much attention owing to emergent phenomena associated with the sublattice degree of freedom. The newly discovered heavy fermion superconductor CeRh$_2$As$_2$ is considered to…
The electronic structures and topological properties of transition metal dipnictides $XPn_2$ ($X$=Ta, Nb; $Pn$=P, As, Sb) have been systematically studied using first-principles calculations. In addition to small bulk Fermi surfaces, the…
LaNiGa2 is a time-reversal symmetry breaking superconductor with symmetry protected band crossings, making it an ideal platform for investigating the interplay between unconventional superconductivity and electronic structure topology. Here…
We studied the superconducting pairing symmetry based on a newly constructed tight-binding model of La$_3$Ni$_2$O$_7$ under pressure, where the $\gamma$ band sinks below the Fermi level and does not form the Fermi surface. The…
We use relativistic ab-initio methods combined with model Hamiltonian approaches to analyze the normal-phase electronic and structural properties of the recently discovered WP superconductor. Remarkably, the outcomes of such study can be…
Cosine-shaped bands that occur in DFT-based electronic band structures for MgB2 are further analyzed with calculations along reciprocal directions parallel to the high symmetry G-A direction at regular intervals along G-M. Band degeneracies…
Pd$_3$Bi$_2$Se$_2$ is a rare realization of a superconducting metal with a non-zero $Z_2$ topological invariant. We report the growth of high-quality single crystals of layered Pd$_3$Bi$_2$Se$_2$ with a superconducting transition at $T_c$ ~…
Topological metals and semimetals (TMs) have recently drawn significant interest. These materials give rise to condensed matter realizations of many important concepts in high-energy physics, leading to wide-ranging protected properties in…
Recently, multifold fermions characterized by band crossings with multifold degeneracy and Fermi surfaces with nontrivial Chern numbers have been discovered experimentally in AlPt[arXiv:1812.03310] and…
The discovery of high-T$_c$ superconductivity in La$_3$Ni$_2$O$_7$ has opened the door to a new route to high temperature superconductivity, distinct from that in cuprates and iron-based materials. Yet, despite intense recent activity, we…
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…
We study the low-energy surface electronic structure of the transition-metal dichalcogenide superconductor PdTe$_2$ by spin- and angle-resolved photoemission, scanning tunneling microscopy, and density-functional theory-based supercell…
Topological semimetals exhibit band crossings near the Fermi energy, which are protected by the nontrivial topological character of the wave functions. In many cases, these topological band degeneracies give rise to exotic surface states…
We study a new class of non-Hermitian topological phases in three dimension in the absence of any symmetry, where the topological robust band degeneracies are Hopf-link exceptional lines. As a concrete example, we investigate the…
In the search of topological superconductors, nailing down the Fermiology of the normal state is as crucial a prerequisite as unraveling the superconducting pairing symmetry. In particular, the number of time-reversal-invariant momenta in…
Recently, evidences of superconductivity (SC) with onset $T_c$ above the McMillan limit have been detected in the La$_3$Ni$_2$O$_7$ ultrathin film grown on the LaSrAlO$_4$ substrate at ambient pressure. This progress opens a new era in the…
We propose helical topological superconductivity away from the Fermi surface in three-dimensional time-reversal-symmetric odd-parity multiband superconductors. In these systems, pairing between electrons originating from different bands is…