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arXiv · 1401.0246

Three Dimensional Metallic and Two Dimensional Insulating Behavior in Tantalum Dichalcogenides

Pierre Darancet·Andrew J. Millis·Chris A. Marianetti
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Abstract

Using density functional theory with added on-site interactions (DFT+U), we study the electronic structure of bulk, monolayer, and bilayer of the layered transition-metal dichalcogenide $1T-TaS_2$. We show that a two-dimensional spin--$\frac{1}{2}$ Mott-phase exists for the monolayer in the charge-density wave state (CDW) and that such a phase is systematically destroyed by packing of the distorted layers leading to a one dimensional metal for bulk, CDW-distorted TaS$_2$. The latter finding is in contrast with previous DMFT predictions --disagreement we explain by the weak effective interaction felt by the electrons in the CDW state. Experimental observations of insulating behavior may arise from disorder due to stacking faults.

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Pierre Darancet, Andrew J. Millis, Chris A. Marianetti. 2014-01-01. Three Dimensional Metallic and Two Dimensional Insulating Behavior in Tantalum Dichalcogenides. https://doi.org/10.1103/physrevb.90.045134

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