Influence of the spin-orbit coupling in the structural and electronic

properties of Ir chains

Víctor M. García Suárez1, Lucas Fernádez-Seivane2,

Colin J. Lambert1 and Jaime Ferrer2

1Physics Department, Lancaster University2Departamento de Física, Universidad de Oviedo

Simulations of monoatomic chains

- Ab initio method

- Au, Pt and Ir chains

Infinite iridium chains

- Structural and electronic properties

- Transport properties

Simulations of monoatomic chains

Smeagol (DFT Hamiltonian from SIESTA)

- Scattering problem

- Density matrix and transmission

LH RH

LMV MRV

MH

EEEfErGr F )d(),(ˆIm1

)(ˆ

)](ˆˆˆˆ[tr)( EGGET LR

Simulations of monoatomic chains

Monoatomic chains

- Conductance in the last

plateau between 2.2 and

0.9 G0

- Oscillations with

negative slope (Pt & Ir)

- Distance between peaks:

~ 2.3 ÅSmit et al. PRL 91, 076805 (2003)

Simulations of monoatomic chains

Infinite chains

- Local zigzag

minimum

- N. of channels

halved in the

zigzag case

compared to

the linear case

Zigzag Linear

PRL 95, 256804 (2005)

Simulations of monoatomic chains

Infinite iridium chains

Infinite iridium chainsStructural configurations:

linear, zigzag and ladder

ladder

linear

zigzag

Infinite iridium chainsMagnetic configurations:

high and low spin

Infinite iridium chainsSpin-orbit coupling effects

Different spin orientations

depending on dz

90, 00

90, 9000, 00

Infinite iridium chainsThe magnetic modulus also changes

Infinite iridium chainsTransmission channels in the

spin-polarized case

Infinite iridium chainsTransmission channels with spin-orbit

- Linear chains

Infinite iridium chainsTransmission channels with spin-orbit

- Linear vs zigzag chains in the linear regime

Infinite iridium chainsTransmission channels with spin-orbit

- Zigzag chains

Infinite iridium chainsBand structure

Infinite iridium chainsTransmission channels in zigzag chains

Spin polarized vs spin-orbit

Conclusions

- Zigzag and ladder chains are more stable

than linear chains

- Different magnetic configurations as a

consequence of the spin-orbit coupling

- The inclusion of the spin-orbit alters

dramatically the number of channels