Scientific Highlights
Nodeless superconductivity and its evolution with pressure in the layered dirac semimetal 2M-WS2
Recently, the transition metal dichalcogenide (TMD) system 2M-WS2 has been identified as a Dirac semimetal exhibiting both superconductivity with the highest Tc ~ 8.5 K among all the TMD materials and topological surface states. Here we report on muon spin rotation (μSR) and density functional theory studies of microscopic SC properties and the electronic structure in 2M-WS2 at ambient and under hydrostatic pressures (pmax = 1.9 GPa).
Experimental signatures of a three-dimensional quantum spin liquid in effective spin-1/2 Ce2Zr2O7 pyrochlore
A quantum spin liquid is a state of matter where unpaired electrons’ spins, although entangled, do not show magnetic order even at the zero temperature. The realization of a quantum spin liquid is a long-sought goal in condensed-matter physics.
Critical fields of Nb3Sn prepared for superconducting cavities
Nb3Sn is currently the most promising material other than niobium for future superconducting radiofrequency cavities. Critical fields above 120 mT in pulsed operation and about 80 mT in CW have been achieved in cavity tests. This is large compared to the lower critical field as derived from the London penetration depth, extracted from low field surface impedance measurements.
Phase transition in the cuprates from a magnetic-field-free stiffness meter viewpoint
A method to measure the superconducting (SC) stiffness tensor ρs, without subjecting the sample to external magnetic field, is applied to La1.875Sr0.125CuO4. The method is based on the London equation J=-ρsA, where J is the current density and A is the vector potential which is applied in the SC state.
Kondo screening in a charge-insulating spinon metal
The Kondo effect, an eminent manifestation of many-body physics in condensed matter, is traditionally explained as exchange scattering of conduction electrons on a spinful impurity in a metal. The resulting screening of the impurity's local moment by the electron Fermi sea is characterized by a Kondo temperature TK, below which the system enters a strongly coupled regime.
Elementary excitation in the spin-stripe phase in quantum chains
Elementary excitations in condensed matter capture the complex many-body dynamics of interacting basic entities in a simple quasiparticle picture. In magnetic systems the most established quasiparticles are magnons, collective excitations that reside in ordered spin structures, and spinons, their fractional counterparts that emerge in disordered, yet correlated spin states.
Exotic Low-Energy Excitations Emergent in the Random Kitaev Magnet Cu2IrO3
We report on magnetization M(H), dc and ac magnetic susceptibility Χ(T), specific heat Cm(T) and muon spin relaxation (μSR) measurements of the Kitaev honeycomb iridate Cu2IrO3 with quenched disorder. In spite of the chemical disorders, we find no indication of spin glass down to 260 mK from the Cm(T) and μSR data.
Negative flat band magnetism in a spin–orbit-coupled correlated kagome magnet
Electronic systems with flat bands are predicted to be a fertile ground for hosting emergent phenomena including unconven- tional magnetism and superconductivity, but materials that manifest this feature are rare. Here, we use scanning tunnelling microscopy to elucidate the atomically resolved electronic states and their magnetic response in the kagome magnet Co3Sn2S2.
Search for the Magnetic Monopole at a Magnetoelectric Surface
We show, by solving Maxwell’s equations, that an electric charge on the surface of a slab of a linear magnetoelectric material generates an image magnetic monopole below the surface provided that the magnetoelectric has a diagonal component in its magnetoelectric response. The image monopole, in turn, generates an ideal monopolar magnetic field outside of the slab.