相关论文: Weyl-triplons in SrCu2(BO3)2
The celebrated Shastry Sutherland model has a gapped dimer singlet ground state. The material SrCu$_2$(BO$_3$)$_2$ serves as a good realization of this model, upto small anisotropies arising from Dzyaloshinskii-Moriya (DM) interactions. The…
The study of topological magnetic excitations has attracted widespread attention in the past few years. In this thesis, I have studied some examples of novel topological magnonic phases/phenomena in low-dimensional quantum magnets. The…
We introduce an effective 2-dimer tight-binding model for the family of Shastry-Sutherland models with geometrically tunable triplon excitations. The Rashba pseudospin-orbit coupling induced by the tilted external magnetic field leads to…
The quantum magnet SrCu$_2($BO$_3)_2$ and its remarkably accurate theoretical description, the spin-$1/2$ Shastry-Sutherland model, host a variety of intriguing phenomena such as a dimer ground state with a nearly flat band of triplon…
Recent discovery of both gapped and gapless topological phases in weakly correlated electron systems has introduced various relativistic particles and a number of exotic phenomena in condensed matter physics. The Weyl fermion is a prominent…
Following the discovery of topological insulators (TIs), topological Dirac/Weyl semimetal has attracted much recent interest. A prevailing mechanism for the formation of Weyl points is by breaking time-reversal symmetry (TRS) or spatial…
The twin discoveries of the quantum Hall effect, in the 1980's, and of topological band insulators, in the 2000's, were landmarks in physics that enriched our view of the electronic properties of solids. In a nutshell, these discoveries…
The temperature dependence of the gapped triplet excitations (triplons) in the 2D Shastry-Sutherland quantum magnet SrCu$_2$(BO$_3$)$_2$ is studied by means of inelastic neutron scattering. The excitation amplitude rapidly decreases as a…
We performed inelastic neutron scattering on the 2D Shastry-Sutherland system SrCu2(11BO3)2 with an exact dimer ground state. Three energy levels at around 3, 5 and 9 meV were observed at 1.7 K. The lowest excitation at 3.0 meV is almost…
Microscopic theory of the normal-to-superconductor coexistence line of a 2D two-band Weyl superconductor subjected to magnetic field is constructed. It is shown that a Weyl semi-metal that is nonsuperconducting or having a small critical…
The Shastry-Sutherland compound SrCu$_2$(BO$_3$)$_2$ constituting orthogonally coupled dimers harbors a $S=0$ singlet ground state. The confluence of strong interdimer interaction and frustration engenders a spectrum of low-energy…
Weyl fermions are massless chiral quasiparticles existing in materials known as Weyl semimetals. Topological surface states, associated with the unusual electronic structure in the Weyl semimetals, have been recently demonstrated in linear…
In this paper, a Bose-Hubbard extension of a Weyl semimetal is proposed that can be realized for ultracold atoms using laser assisted tunneling and Feshbach resonance technique in three dimensional optical lattices. The global phase diagram…
We propose a theoretical scheme to realize two-dimensional higher-order Weyl semimetals using a trilayer topological insulator film coupled with a d-wave altermagnet. Our results show that the trilayer topological insulator exhibits…
Weyl points, synthetic magnetic monopoles in the 3D momentum space, are the key features of topological Weyl semimetals. The observation of Weyl points in ultracold atomic gases usually relies on the realization of high-dimensional…
Hall effect of topological quantum materials often reveals essential new physics and possesses potential for application. Magnetic Weyl semimetal is one especially interesting example that hosts an interplay between the spontaneous…
We have found a ferromagnetic Weyl semimetal (WSM) in half metallic Co$_3$Sn$_2$Se$_2$. The three pairs of Weyl points near Fermi level (E$_F$) are derived from nodal lines gapped by spin-orbit coupling (SOC). Though the Weyl points are…
We study topological properties of one-triplon bands in an extended Shastry-Sutherland model relevant for the frustrated quantum magnet SrCu_2(BO_3)_2. To this end perturbative continuous unitary transformations are applied about the…
The "Hydrogen atom" of magnetic Weyl semimetals, with the minimum number of Weyl points, have received growing attention recently due to the possible presence of Weyl-related phenomena. Here, we report a nontrivial electronic structure of…
We discuss the possibility of realizing Weyl semimetal phase in the magnetically doped topological band insulators. When the magnetic moments are ferromagnetically polarized, we show that there are three phases in the system upon the…