Publications by authors named "L C Chapon"

Transition-metal dichalcogenides (TMDs) offer an ideal platform to experimentally realize Dirac fermions. However, typically these exotic quasiparticles are located far away from the Fermi level, limiting the contribution of Dirac-like carriers to the transport properties. Here we show that NiTe hosts both bulk Type-II Dirac points and topological surface states.

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Article Synopsis
  • An exciton is a bosonic quasiparticle formed from electron-hole pairs and has potential for Bose-Einstein condensation in various materials.
  • Recent findings show a spin-orbit-entangled exciton state in the antiferromagnetic van der Waals material NiPS below 150 kelvin, which is linked to many-body states like the Zhang-Rice singlet.
  • Utilizing three spectroscopy methods, researchers confirmed this exciton has a very narrow linewidth below 50 kelvin, suggesting that van der Waals magnets could be valuable for researching coherent many-body excitons.
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The analysis of three-dimensional neutron spin polarization vectors, using a technique referred to as spherical neutron polarimetry (SNP), is a very powerful means of determining complex magnetic structures in magnetic materials. However, the requirement to maintain neutrons in a highly polarized state has made it difficult to use this technique in conjunction with extreme experimental conditions. We have developed a high pressure cell made completely of nonmagnetic materials and having no effect on neutron polarizations.

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(ND)[FeCl(DO)] represents a promising example of the hybrid molecular/inorganic approach to create materials with strong magneto-electric coupling. Neutron spherical polarimetry, which is directly sensitive to the absolute magnetic configuration and domain population, has been used in this work to unambiguously prove the multiferroicity of this material. We demonstrate that the application of an electric field upon cooling results in the stabilization of a single-cycloidal magnetic domain below 6.

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The complexity embedded in condensed matter fertilizes the discovery of new states of matter, enriched by ingredients like frustration. Illustrating examples in magnetic systems are Kitaev spin liquids, skyrmions phases, or spin ices. These unconventional ground states support exotic excitations, for example the magnetic charges in spin ices, also called monopoles.

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