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arXiv · 1707.09310

Multiple crossovers and coherent states in a Mott-Peierls insulator

O. Nájera·M. Civelli·V. Dobrosavljević·M. J. Rozenberg
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Abstract

We consider the dimer Hubbard model within Dynamical Mean Field Theory to study the interplay and competition between Mott and Peierls physics. We describe the various metal-insulator transition lines of the phase diagram and the break down of the different solutions that occur along them. We focus on the specific issue of the debated Mott-Peierls insulator crossover and describe the systematic evolution of the electronic structure across the phase diagram. We found that at low intra-dimer hopping the emerging local magnetic moments can unbind above a characteristic singlet temperature $T^*$. Upon increasing the inter-dimer hopping subtle changes occur in the electronic structure. Notably, we find Hubbard bands of a mix character with coherent and incoherent excitations. We argue that this state is relevant for VO$_2$ and its signatures may be observed in spectroscopic studies, and possibly through pump-probe experiments.

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O. Nájera, M. Civelli, V. Dobrosavljević, M. J. Rozenberg. 2017-10-20. Multiple crossovers and coherent states in a Mott-Peierls insulator. https://doi.org/10.1103/physrevb.97.045108

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