Related papers: Inter-node superconductivity in strained Weyl semi…
A recent experiment on Nb-doped Bi2Se3 showed that zero field magnetization appears below the superconducting transition temperature. This gives evidence that the superconducting state breaks time-reversal symmetry spontaneously and…
Weyl nodal loop semimetals (WNLs) host a closed nodal line loop Fermi surface in the bulk, protected zero-energy flat band, or drumhead, surface states, and strong spin-polarization. The large density of states of the drumhead states makes…
A generalization of the Cooper pairing mechanism is proposed which allows for a triplet state of lower energy. This is achieved by incorporating spin into the canonical commutation relations and by modifying the $\delta$ potential contact…
We present new results for the properties of phases and phase transitions in spin-triplet ferromagnetic superconductors. The superconductivity of the mixed phase of coexistence of ferromagnetism and unconventional superconductivity is…
Recent studies show superconductivity provides new perspectives on spintronics. We study a heterostructure composed of an s-wave superconductor and a cubic chiral-magnet that can stabilize a topological spin texture, a skyrmion. We propose…
We study three dimensional systems where the parent metallic state contains a loop of Weyl or Dirac points. We introduce the minimal $\vec{k} \cdot \vec{p}$ Hamiltonian , and discuss its symmetries. Guided by this symmetry analysis, we…
We present a theory of superconductivity in twisted bilayer graphene in which attraction is generated between electrons on the same honeycomb sublattice when the system is close to a sublattice polarization instability. The resulting Cooper…
We study superconducting states of doped inversion-symmetric Weyl semimetals. Specifically, we consider a lattice model realizing a Weyl semimetal with an inversion symmetry and study the superconducting instability in the presence of a…
The interplay between spin-orbit interaction (SOI) and magnetism produces interesting phenomena in superconductors. When a two-dimensional (2D) system with strong SOI is coupled to an $s$-wave superconductor, an in-plane magnetic field can…
In the presence of a large perpendicular electric field, Bernal-stacked bilayer graphene (BLG) features several broken-symmetry metallic phases as well as magnetic-field-induced superconductivity. The superconducting state is quite fragile,…
The planar Hall effect (PHE), the appearance of an in-plane transverse voltage in the presence of coplanar electric and magnetic fields, has been ascribed to the chiral anomaly and Berry curvature effects in Weyl semimetals. In the presence…
Recent results for the coexistence of ferromagnetism and unconventional superconductivity with spin-triplet Cooper pairing are reviewed on the basis of the quasi-phenomenological Ginzburg-Landau theory. New results are reported. The results…
We theoretically study electrical responses of magnetization in Weyl semimetals. The Weyl semimetal is a new class of topological semimetals, possessing hedgehog type spin textures in momentum space. Because of this peculiar spin texture,…
The massless fermions of a Weyl semimetal come in two species of opposite chirality, in two cones of the band structure. As a consequence, the current $j$ induced in one Weyl cone by a magnetic field $B$ (the chiral magnetic effect, CME) is…
We report a comprehensive neutron scattering study on the spin excitations in the magnetic Weyl semimetal Co$_3$Sn$_2$S$_2$ with quasi-two-dimensional structure. Both in-plane and out-of-plane dispersions of the spin waves are revealed in…
Conventional spin-singlet superconductivity that deeply penetrates into ferromagnets is typically killed by the exchange interaction, which destroys the spin-singlet pairs. Under certain circumstances, however, superconductivity survives…
The existence of pseudomagnetic helicons is predicted for strained Dirac and Weyl materials. The corresponding collective modes are reminiscent of the usual helicons in metals in strong magnetic fields but can exist even without a magnetic…
This paper theoretically discusses the spin current in spin-triplet superconductor / insulator / spin-triplet superconductor junctions. At low temperatures, a midgap Andreev resonant state anomalously enhances not only the charge current…
Recent results about the coexistence of ferromagnetism and unconventional superconductivity with spin-triplet Cooper pairing are reviewed on the basis of the quasi-phenomenological Ginzburg-Landau theory. The superconductivity in the mixed…
The interplay between magnetism and superconductivity is one of the central topics of condensed matter physics, which has recently been put into new light by the discovery of altermagnets. Here, we study this interplay from a fundamental…