Robust semi-Dirac points and unconventional topological phase transitions in doped superconducting Sr2IrO4 tunnel coupled to t2g electron systems

Horsdal, Mats; Hyart, Timo

doi:10.21468/SciPostPhys.3.6.041

SciPost Physics

Robust semi-Dirac points and unconventional topological phase transitions in doped superconducting Sr2IrO4 tunnel coupled to t2g electron systems

Mats Horsdal, Timo Hyart

SciPost Phys. 3, 041 (2017) · published 22 December 2017

doi: 10.21468/SciPostPhys.3.6.041
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Abstract

Semi-Dirac fermions are known to exist at the critical points of topological phase transitions requiring fine-tuning of the parameters. We show that robust semi-Dirac points can appear in a heterostructure consisting of superconducting Sr2IrO4 and a t2g electron system (t2g-ES) without fine-tuning. They are topologically stable in the presence of the symmetries of the model, metallic t2g-ES and a single active band in Sr2IrO4. If the t2g metal is coupled to two different layers of Sr2IrO4 (effectively a multiband superconductor) in a three-layer-structure the semi-Dirac points can split into two stable Dirac points with opposite chiralities. A similar transition can be achieved if the t2g-ES supports intrinsic triplet superconductivity. By considering Sr2RuO4 as an example of a t2g-ES we predict a rich topological phase diagram as a function of various parameters.

TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.3.6.041
TI  - Robust semi-Dirac points and unconventional topological phase transitions in doped superconducting Sr2IrO4 tunnel coupled to t2g electron systems
PY  - 2017/12/22
UR  - https://scipost.org/SciPostPhys.3.6.041
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 3
IS  - 6
SP  - 041
A1  - Horsdal, Mats
AU  - Hyart, Timo
AB  - Semi-Dirac fermions are known to exist at the critical points of topological phase transitions requiring fine-tuning of the parameters. We show that robust semi-Dirac points can appear in a heterostructure consisting of superconducting Sr2IrO4 and a t2g electron system (t2g-ES) without fine-tuning. They are topologically stable in the presence of the symmetries of the model, metallic t2g-ES and a single active band in Sr2IrO4. If the t2g metal is coupled to two different layers of Sr2IrO4 (effectively a multiband superconductor) in a three-layer-structure the semi-Dirac points can split into two stable Dirac points with opposite chiralities. A similar transition can be achieved if the t2g-ES supports intrinsic triplet superconductivity. By considering Sr2RuO4 as an example of a t2g-ES we predict a rich topological phase diagram as a function of various parameters.
ER  -

@Article{10.21468/SciPostPhys.3.6.041,
	title={{Robust semi-Dirac points and unconventional topological phase transitions in doped superconducting Sr2IrO4 tunnel coupled to t2g electron systems}},
	author={Mats Horsdal and Timo Hyart},
	journal={SciPost Phys.},
	volume={3},
	pages={041},
	year={2017},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.3.6.041},
	url={https://scipost.org/10.21468/SciPostPhys.3.6.041},
}

Cited by 4

Ontology / Topics

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Dirac points Sr2IrO4 Superconductivity/superconductors Topological insulators Topological phase transitions Triplet superconductivity t2g electron systems (t2g-ES)

Authors / Affiliations: mappings to Contributors and Organizations

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¹ Mats Horsdal,
² Timo Hyart

Funders for the research work leading to this publication