Slater metal-insulator transition in NaOsO3

The magnetically driven metal-insulator transition was theoretically predicted by Slater in the fifties. We exploit THz and IR spectroscopy to demonstrate that NaOsO3 is the first knwon 3D Slater insulator.

I. Lo Vecchio et al., Scientific Reports 3, 2990 (2013)



In 1951, Slater suggested that antiferromagnetism alone could trigger a metal-insulator transition (MIT). The establishment of a long-range antiferromagnetic order induces an opposite potential on each nearest electron site which doubles the magnetic unit cell. This results in a splitting of the occupied bands and, in case of half-filling, in a gap for charge excitations. We have probed the electrodynamics of NaOsO3 across the MIT by terahertz and infrared spectroscopy. From an analysis of the optical spectral weight we establish that NaOsO3 is a weakly correlated material. 
We also show that, at variance with a Mott-Hubbard MIT, the optical conductivity does not vanish at TMIT as the charge gap opens up in a continuous way in agreement with the second order character of the MIT. Those experimental results clarify the 3D nature of the  MIT in NaOsO3 in terms of the Slater mechanism.

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Infrared evidence of a Slater metal-insulator transition in NaOsO3;
I. Lo Vecchio et al.
Scientific Reports 3, 2990 (2013)

 

 

Last Updated on Saturday, 19 December 2015 10:17