Spin-orbit driven emergent phases in correlated systems: Iridates

Date

Oct 13, 2016

Time

10:30 AM - 11:30 AM

Speaker

Sayantika Bhowal

Affiliation

IACS, Kolkata, India / TU Bergakademie Freiberg

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Grit Rötzer

Description

The effect of spin-orbit coupling (SOC) in correlated electron systems has attracted considerable attention in condensed matter physics as correlations and SOC together can lead to emergent phases like novel jeff=1/2 Mott state, quantum spin-orbital liquid etc. Iridium oxides, commonly known as iridates, have been an excellent playground to reveal such novel phenomena. In this context, 6-H perovskite iridates Ba3MIr2O9 are also quite intriguing as the non magnetic M (=Zn, Y) [1,3] atom provides a knob to tailor the valence (4+, 4.5+) of Ir. In this talk we shall explain the unconventional magnetism in d4 double perovskite iridates. [2] Contrary to the common expectation f spin orbit driven J=0 nonmagnetic state, we find finite moment persists at the Ir site. Our study shows that the band structure effect rather than the crystal field effect to be responsible for this breakdown. The antiferromagnetic superexchange interaction between Ir moments, in general, makes these compounds insulating. References: [1] Abhishek Nag, S. Middey, Sayantika Bhowal, S. K. Panda, Roland Mathieu, J. C. Orain, F. Bert, P. Mendels, P. G. Freeman, M. Mansson, H. M. Ronnow, M. Telling, P. K. Biswas, D. Sheptyakov, S. D. Kaushik, Vasudeva Siruguri, Carlo Meneghini, D. D. Sarma, Indra Dasgupta, and Sugata Ray, Phys. Rev. Lett. 116, 097205 (2016). [2] Sayantika Bhowal, Santu Baidya, Indra Dasgupta, and Tanusri Saha-Dasgupta, Phys. Rev. B 92, 121113(R) (2015). [3] S. K. Panda, S. Bhowal, Ying Li, S. Ganguly, Roser Valenti', L. Nordstrom, and I. Dasgupta, Phys. Rev. B 92, 180403(R) (2015). .

Links

• Seminars at the IFW

Last modified: Oct 13, 2016, 9:40:07 AM