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arXiv · 1505.03277

Nexus and Dirac lines in topological materials

T. T. Heikkila·G. E. Volovik
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Abstract

We consider the $Z_2$ topology of the Dirac lines, i.e., lines of band contacts, on an example of graphite. Four lines --- three with topological charge $N_1=1$ each and one with $N_1=-1$ --- merge together near the H-point and annihilate due to summation law $1+1+1-1=0$. The merging point is similar to the real-space nexus, an analog of the Dirac monopole at which the $Z_2$ strings terminate.

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T. T. Heikkila, G. E. Volovik. 2015-05-13. Nexus and Dirac lines in topological materials. https://doi.org/10.1088/1367-2630%2F17%2F9%2F093019

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