Mott physics in a cluster

GaTa4Se8 is an insulator whose fundamental building blocks are clusters of transition metal Ta4 atoms. The perfect agreement between infrared measurements at high pressures and theoretical calculations demonstrate the almost ideal one-band Mott insulator character of GaTa4Se8.

V. Ta Phuoc et al., Phys. Rev. Lett. 110, 037401 (2013)



GaTa4Se8 is a lacunar spinel chalcogenide undergoing an insulator to metal transition (IMT) under pressure. A resistive switching induced by electric pulses was discovered in this material, making it promising for RRAM applications. It was argued that GaTa4Se8 may belong to a new class of Mott insulators where the relevant entity for electronic correlation is a cluster of transition metals Ta4 rather than a single atomic site. Optical measurements at high pressures demonstrate that GaTa4Se8 is a Mott insulator undergoing a bandwidth- controlled IMT under pressure. The very good agreement between data and theory results from the almost ideal one-band Mott insulator character of GaTa4Se8. In this context, GaTa4Se8 could become the new archetypal Mott insulator ideally suited for future comparisons between experiments and theory.

Retrieve Article

Optical conductivity measurements of GaTa4Se8 at high pressure;
V. Ta Phuoc et al.
Phys. Rev. Lett 110, 037401 (2013)

 

 

 

Last Updated on Saturday, 19 December 2015 10:17