Antiferromagnets are normally thought of as materials with compensated magnetic sublattices. This adds to their technological advantages but complicates readout of the antiferromagnetic state. We demonstrate theoretically the existence of a Dzyaloshinskii-Moriya interaction (DMI), which is determined by the magnetic symmetry classes of Cr_{2}O_{3} surfaces with an in-plane magnetic easy axis.
View Article and Find Full Text PDFThe crystal structures of ANbBrS (A = Rb and Cs) have been refined by single crystal X-ray diffraction, and are found to form highly anisotropic materials based on chains of the triangular Nb cluster core. The Nb cluster core contains seven valence electrons, six of them being assigned to Nb-Nb bonds within the Nb triangle and one unpaired d electron. The presence of this surplus electron gives rise to the formation of correlated electronic states.
View Article and Find Full Text PDFWe establish the sign of the linear magnetoelectric (ME) coefficient,, in chromia, CrO. CrOis the prototypical linear ME material, in which an electric (magnetic) field induces a linearly proportional magnetization (polarization), and a single magnetic domain can be selected by annealing in combined magnetic () and electric () fields. Opposite antiferromagnetic (AFM) domains have opposite ME responses, and which AFM domain corresponds to which sign of response has previously been unclear.
View Article and Find Full Text PDFWe use a combination of density functional theory and Monte Carlo methods to calculate the surface magnetization in magnetoelectric Cr_{2}O_{3} at finite temperatures. Such antiferromagnets, lacking both inversion and time-reversal symmetries, are required by symmetry to possess an uncompensated magnetization density on particular surface terminations. Here, we first show that the uppermost layer of magnetic moments on the ideal (001) surface remains paramagnetic at the bulk Néel temperature, bringing the theoretical estimate of surface magnetization density in line with experiment.
View Article and Find Full Text PDFTransition-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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