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Properties of liquids at solid interfaces play a central role in numerous important processes in nature. Nuclear magnetic resonance (NMR) is particularly useful for probing liquid/graphitic carbon interfacial properties. In particular, the nucleus-independent chemical shift (NICS) provides a sensitive measure of the distance between adsorbates and the graphitic carbon surface on the subnanometer scale, enabling NMR to acquire subnanometer scale spatial resolution. Here, by combining the information on thermodynamics obtained from in situ NMR-detected water isotherm and spatially resolved information on structure and dynamics obtained by NICS-resolved NMR, the microscopic process of water nucleation and growth inside the micropore of activated carbons is investigated. The formation of water clusters at surface sites, the cooperative growth process of pore bridging, and the final stage of horizontal pore filling are revealed in detail, demonstrating the potential of this comprehensive NMR approach for studying microscopic mechanisms at solid/liquid interfaces including electrochemical processes.

Using helium atom scattering to identify adsorbate interactions and separate the effects of long and short range forces.

The adsorption of sodium on Ru(0001) is studied using $^3$He spin-echo spectroscopy (HeSE), molecular dynamics simulations (MD) and density functional theory (DFT). In the multi-layer regime, an analysis of helium...

Incorporating relativistic physics into quantum tunneling can lead to exotic behavior such as perfect transmission through Klein tunneling. Here, we probed the tunneling properties of spin-momentum-locked relativistic fermions by designing and implementing a tunneling geometry that uses nanowires of the topological Kondo insulator candidate samarium hexaboride. The nanowires are attached to the end of scanning tunneling microscope tips and used to image the bicollinear stripe spin order in the antiferromagnet Fe 1.03 Te with a Neel temperature of about 50 kelvin. The antiferromagnetic stripes become invisible above 10 kelvin concomitant with the suppression of the topological surface states in the tip. We further demonstrate that the direction of spin polarization is tied to the tunneling direction. Our technique establishes samarium hexaboride nanowires as ideal conduits for spin-polarized currents.

Significance There is an intense ongoing search for two-level quantum systems with long lifetimes for applications in quantum communication and computation. Much research has been focused on studying isolated spins in semiconductors or band insulators. Mott insulators provide an interesting alternative platform but have been far less explored. In this work we use a technique capable of resolving individual spins at atomic length scales, to measure the two-level switching of spin states in 1T-TaS 2 . We find quasi-1D chains of spin-1/2 electrons embedded in 1T-TaS 2 which have exceptionally long lifetimes. The discovery of long-lived spin states in a tractable van der Waal material opens doors to using Mott systems in future quantum information applications.

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Weyl semimetal is a unique topological phase with topologically protected band crossings in the bulk and robust surface states called Fermi arcs. Weyl nodes always appear in pairs with opposite chiralities, and they need to have either time‐reversal or inversion symmetry broken. When the time‐reversal symmetry is broken the minimum number of Weyl points (WPs) is two. If these WPs are located at the Fermi level, they form an ideal Weyl semimetal (WSM). In this study, intrinsic ferromagnetic (FM) EuCd2As2 are grown, predicted to be an ideal WSM and studied its electronic structure by angle‐resolved photoemission spectroscopy, and scanning tunneling microscopy which agrees closely with the first principles calculations. Moreover, anomalous Hall conductivity and Nernst effect are observed, resulting from the non‐zero Berry curvature, and the topological Hall effect arising from changes in the band structure caused by spin canting produced by magnetic fields. These findings can help realize several exotic quantum phenomena in inorganic topological materials that are otherwise difficult to assess because of the presence of multiple pairs of Weyl nodes.