Direct evidence of hidden local spin polarization in a centrosymmetric superconductor LaO0.55 F0.45BiS2

  title={Direct evidence of hidden local spin polarization in a centrosymmetric superconductor LaO0.55 F0.45BiS2},
  author={Shilong Wu and Kazuki Sumida and Koji Miyamoto and Kazuaki Taguchi and Tomoki Yoshikawa and Akio Kimura and Yoshifumi Ueda and Masashi Arita and Masanori Nagao and Satoshi Watauchi and Isao Tanaka and Taichi Okuda},
  journal={Nature Communications},
Conventional Rashba spin polarization is caused by the combination of strong spin–orbit interaction and spatial inversion asymmetry. However, Rashba–Dresselhaus-type spin-split states are predicted in the centrosymmetric LaOBiS2 system by recent theory, which stem from the local inversion asymmetry of active BiS2 layer. By performing high-resolution spin- and angle-resolved photoemission spectroscopy, we have investigated the electronic band structure and spin texture of superconductor LaO0… 
24 Citations
Revealing hidden spin-momentum locking in a high-temperature cuprate superconductor
Using spin- and angle-resolved photoemission spectroscopy, one of the most studied cuprate superconductors, Bi2212, has a nontrivial spin texture with a spin-momentum locking that circles the Brillouin zone center and aspin-layer locking that allows states of opposite spin to be localized in different parts of the unit cell.
Hidden bulk and surface effects in the spin polarization of the nodal-line semimetal ZrSiTe
In non-magnetic materials the combination of inversion symmetry breaking (ISB) and spin-orbit coupling (SOC) determines the spin polarization of the band structure. However, a local spin polarization
Observation of Spin-Momentum-Layer Locking in a Centrosymmetric Crystal.
This work demonstrates the existence of momentum-dependent hidden spin polarization and uncovers the microscopic mechanism of spin, momentum, and layer locking to each other, thus shedding light on the design metrics for future spintronic materials.
Spin-orbital hallmarks of unconventional superconductors without inversion symmetry
The spin-orbital polarization of superconducting excitations in momentum space is shown to provide distinctive marks of unconventional pairing in the presence of inversion symmetry breaking. Taking
Band splitting with vanishing spin polarizations in noncentrosymmetric crystals
The authors identify an unconventional spin-orbit effect in high-symmetry situations that leads to a linear magnetoelectric coupling in reciprocal space, which could be employed to tune the spin polarization with an external electric field.
Nonhelical spin texture in the normal states of the centrosymmetric superconductor β−PdBi2
A nonhelical spin texture was observed in the centrosymmetric superconductor beta-PdBi2 using an imaging-type spin- and angle-resolved spectroscopy. The observed surface and bulk states near the
Transverse Rashba effect and unconventional magnetocrystalline anisotropy in graphene-nanoribbon-based centrosymmetric antiferromagnet
  • Weifeng Xie, Yu Song, X. Zuo
  • Physics
  • 2021
Abstract The transverse Rashba effect in a centrosymmetric antiferromagnet materialized by double-Gd-adsorbed graphene nanoribbon is investigated via the first-principle calculations. The Rashba
Field-induced transition within the superconducting state of CeRh2As2
The researchers ascribe the unusual properties of CeRh2As2 to its crystal structure, which is globally centrosymmetric but consists of noncentrosyMMetric layers, and establish that the superconducting critical field of its high-field phase is as high as 14 tesla, even though the transition temperature is only 0.26 kelvin.
Extremely high upper critical field in BiCh2-based (Ch: S and Se) layered superconductor LaO0.5F0.5BiS2−xSex (x = 0.22 and 0.69)
This study focuses on a BiCh 2 -based (Ch: S, Se) layered superconductor, as a system with local inversion asymmetry, because spin polarisation based on the Rashba–Dresselhaus-type spin–orbit coupling has been observed in centrosymmetric BiCh 1 -based LaOBiS 2 systems.
Uncovering and tailoring hidden Rashba spin–orbit splitting in centrosymmetric crystals
It is demonstrated that the spin splitting in the R-2 effect is enforced by specific symmetries, such as non-symmorphic symmetry in the present example, which ensures that the pertinent spin wavefunctions segregate spatially on just one of the two inversion-partner sectors and thus avoid compensation.


Direct observation of spin-layer locking by local Rashba effect in monolayer semiconducting PtSe2 film
The observation of helical spin texture in monolayer, centrosymmetric and semiconducting PtSe2 film without the characteristic spin splitting in conventional Rashba effect (R-1) is reported.
Direct observation of spin-polarized bulk bands in an inversion-symmetric semiconductor
The coupling between spin, valley and layer degrees of freedom in transition-metal dichalcogenides is shown to give rise to spin-polarized electron states, providing opportunities to create and
Giant Rashba-type spin splitting in bulk BiTeI.
The finding of a huge spin-orbit interaction effect in a polar semiconductor composed of heavy elements, BiTeI, where the bulk carriers are ruled by large Rashba-likespin splitting is described, confirming that the spin splitting is indeed derived from bulk atomic configurations.
Quasi 2D electronic states with high spin-polarization in centrosymmetric MoS2 bulk crystals
The first observation of this type of compensated polarization in MoS2 bulk crystals is presented, using spin- and angle-resolved photoemission spectroscopy (ARPES) and it is shown that this spin-layer locking leads to the observation of highly spin-polarized bands in ARPES since these states are almost completely confined within two dimensions.
Quasiparticle dynamics and spin-orbital texture of the SrTiO3 two-dimensional electron gas.
It is demonstrated that angle-resolved photoemission can directly image the quasiparticle dynamics of the d-electron subband ladder of this complex-oxide 2DEG, uncovering how quantum confinement and inversion symmetry breaking collectively tune the delicate interplay of charge, spin, orbital and lattice degrees of freedom in this system.
Tunable Rashba effect in two-dimensional LaOBiS2 films: ultrathin candidates for spin field effect transistors.
It is predicted that the stable 2D LaOBiS2 with only 1 nm of thickness can produce remarkable Rashba spin splitting with a magnitude of 100 meV, and an advanced Datta-Das SFET model is proposed that consists of dual gates and 2DLaOBi s2 channels by selecting different Rashba states to achieve the on-off switch via electric fields.
Fermi-surface topology and pairing symmetry in BiS 2 -based layered superconductors
Abstract In order to clarify superconducting properties of BiS2-based layered superconductors LaO 1 − x F x BiS 2 , we evaluate the superconducting transition temperature T c and analyze the gap
Triplet pairing and possible weak topological superconductivity in BiS 2 -based superconductors
We show that the newly discovered BiS$_2$-based superconductors may have a dominant triplet pairing component, in addition to a subdominant singlet component arising from the spin-orbital coupling.
Electrically tunable multiple Dirac cones in thin films of the (LaO)2(SbSe2)2 family of materials.
A new Dirac system with eight Dirac cones in thin films of the (LaO)2(SbSe2)2 family of materials is proposed, which has the advantage in its tunability: the existence of gapless Dirac cone, their positions, Fermi velocities and anisotropy all can be controlled by an experimentally feasible electric field.
Spin structure of the Shockley surface state on Au(111)
The free-electron like surface state on the (111) surface of gold shows a splitting into two parabolic subbands induced by the spin orbit interaction. Spin-resolved high-resolution photoemission