TY - JOUR
KW - Thin films
KW - Perovskite
KW - Heavy metals
KW - Logic devices
KW - Iridium compounds
KW - Carrier concentration
KW - Conversion efficiency
KW - Electric insulators
KW - Locks (fasteners)
KW - Strontium
KW - Strontium compounds
KW - Anticorrelation
KW - Electronic systems
KW - Fermi wave vectors
KW - Interconversions
KW - Measurement techniques
KW - Spin conversion
KW - Spin-logic devices
KW - Two-materials
AU - A.S Everhardt
AU - M Dc
AU - X Huang
AU - S Sayed
AU - T.A Gosavi
AU - Y Tang
AU - C.-C Lin
AU - S Manipatruni
AU - I.A Young
AU - S Datta
AU - J.-P Wang
AU - Ramamoorthy Ramesh
AB - Efficient charge to spin conversion is important for low-power spin logic devices. Spin and charge interconversion is commonly performed using heavy metals and topological insulators, while the field of oxides is not yet fully explored. Strontium iridate thin films were grown, where the different crystal structures form a perfect playground to understand the key factors in obtaining high charge to spin conversion efficiency (i.e., large spin Hall angle). It was found that the semiconducting Sr2IrO4 has a spin Hall angle of ∼0.1 (depending on measurement technique), which is promising for a spin-orbit coupled electronic system and comparable to Pt. In contrast, the perovskite SrIrO3, reported to have a Dirac cone near the Fermi level, has a larger spin Hall angle of 0.3-0.4 degrees. The largest difference between the two materials is a large degree of spin-momentum locking in SrIrO3, comparable to known topological insulators. A simple semiclassical relationship is found where the spin Hall angle increases for higher degrees of spin-momentum locking and it also increases for lower Fermi wave vectors. This relationship is then able to explain the decreased spin Hall angle below 10 nm film thickness in SrIrO3, by relating it to the correspondingly higher carrier concentration (related to the higher Fermi wave vector). Breaking the commonly believed anticorrelation between resistivity and carrier concentration paves a pathway to lower power losses due to resistance while keeping large spin Hall angles. © 2019 American Physical Society.
BT - Physical Review Materials
DO - 10.1103/PhysRevMaterials.3.051201
LA - eng
M1 - 5
N1 - cited By 1
N2 - Efficient charge to spin conversion is important for low-power spin logic devices. Spin and charge interconversion is commonly performed using heavy metals and topological insulators, while the field of oxides is not yet fully explored. Strontium iridate thin films were grown, where the different crystal structures form a perfect playground to understand the key factors in obtaining high charge to spin conversion efficiency (i.e., large spin Hall angle). It was found that the semiconducting Sr2IrO4 has a spin Hall angle of ∼0.1 (depending on measurement technique), which is promising for a spin-orbit coupled electronic system and comparable to Pt. In contrast, the perovskite SrIrO3, reported to have a Dirac cone near the Fermi level, has a larger spin Hall angle of 0.3-0.4 degrees. The largest difference between the two materials is a large degree of spin-momentum locking in SrIrO3, comparable to known topological insulators. A simple semiclassical relationship is found where the spin Hall angle increases for higher degrees of spin-momentum locking and it also increases for lower Fermi wave vectors. This relationship is then able to explain the decreased spin Hall angle below 10 nm film thickness in SrIrO3, by relating it to the correspondingly higher carrier concentration (related to the higher Fermi wave vector). Breaking the commonly believed anticorrelation between resistivity and carrier concentration paves a pathway to lower power losses due to resistance while keeping large spin Hall angles. © 2019 American Physical Society.
PB - American Physical Society
PY - 2019
T2 - Physical Review Materials
TI - Tunable charge to spin conversion in strontium iridate thin films
VL - 3
SN - 24759953
ER -