Related papers: Interaction Driven Subgap Spin Exciton in the Kond…
Samarium hexaboride (SmB$_6$) is the first strongly correlated material with a recognized non-trivial band-structure topology. Its electron correlations are seen by inelastic neutron scattering as a coherent collective excitation at the…
The spin dynamics of mixed-valence YbB12 has been studied by inelastic neutron scattering on a high-quality single crystal. In the Kondo-insulating regime realized at low temperature, the spectra exhibit a spin-gap structure with two sharp,…
The Kondo semiconductor $Yb B_{12}$ exhibits a spin and charge gap of approximately 15 meV. Close to the gap energy narrow dispersive collective excitations were identified by previous inelastic neutron scattering experiments. We present a…
The compound SmB$_6$ is a Kondo Insulator, where the lowest-energy bulk electronic excitations are spin excitons. It also has surface states that are subjected to strong spin-orbit coupling. It has been suggested that SmB$_6$ is also a…
The Kondo insulator SmB6 is purported to develop into a robust topological insulator at low temperature. Yet there are several puzzling and unexplained physical properties of the insulating bulk. It has been proposed that bulk spin excitons…
Topological insulators give rise to exquisite electronic properties due to their spin-momentum locked Dirac-cone-like band structure. Recently, it has been suggested that the required opposite parities between valence and conduction band…
SmB6 is a proposed topological Kondo insulator where the presence of topological nontriviality can be tuned by variations in the Sm valence. Experimentally, Sm valence can be changed by tuning stoichiometry of SmB6. We show that Raman…
As an exemplary Kondo insulator, SmB6 has been studied for several decades; however, direct evidence for the development of the Kondo coherent state and the evolution of the electronic structure in the material has not been obtained due to…
We performed an inelastic neutron scattering experiment on a polycrystalline sample of a helimagnet Ni$_2$InSbO$_6$ to construct the spin Hamiltonian. Well-defined spin-wave excitation with a band energy of 20 meV was observed below $T_{N}…
Recent theoretical calculations and experimental results suggest that the strongly correlated material SmB$_{6}$ may be a realization of a topological Kondo insulator. We have performed an angle-resolved photoemission spectroscopy study on…
In Kondo insulators the many-body Kondo lattice effect drives the formation of bands containing heavy charge carriers with a hybridization gap, leading to insulating properties. These renormalized bands can host non-trivial topologies…
The heavy quasiparticle bands in Kondo materials which originate in the hybridization of f- and conduction electrons exhibit numerous, sometimes coexisting, broken symmetry phases. Most notable are unconventional superconductivity,…
We use scanning tunneling microscopy to investigate the (001) surface of cleaved SmB6 Kondo insulator. Variable temperature dI/dV spectroscopy up to 60 K reveals a gap-like density of state suppression around the Fermi level, which is due…
Magnetically mediated Cooper pairing is generally regarded as a key to establish the unified mechanism of unconventional superconductivity. One crucial evidence is the neutron spin resonance arising in the superconducting state, which is…
Motivated by the recent experimental observations of quantum oscillations in the Kondo insulators SmB$_6$ and YbB$_{12}$, we study magneto-optical conductivity of Kondo insulators. We show that there exist non-trivial cyclotron resonance…
Cold neutron spectroscopy was performed on CeNi_{1-x}Cu_xSn to investigate how the magnetic gap in the 'Kondo insulator' CeNiSn is destroyed by temperature (T), chemical substitution (x), and external magnetic field. Upon doping, the spin…
In order to better understand Kondo insulators, we have studied both the symmetric and asymmetric Anderson lattices at half-filling in one dimension using the density matrix formulation of the numerical renormalization group. We have…
We investigate the linear and nonlinear dc transport through an interacting quantum dot connected to two ferromagnetic electrodes around Kondo regime with spin-flip scattering in the dot. Using a slave-boson mean field approach for the…
Topological Kondo insulators are a new class of topological insulators in which metallic surface states protected by topological invariants reside in the bulk band gap at low temperatures. Unlike other three-dimensional topological…
In the Anderson lattice model for a mixed-valent system, the $d-f$ hybridization can possess a $p$-wave symmetry. The strongly-correlated insulating phase in the mean-field approximation is shown to be a $p$-wave Bose condensate of excitons…