Antiferromagnetic State in κ-type Molecular Conductors: Spin Splitting and Mott Gap

Boron adsorption induces a heavily localized state right at the Fermi level only in the family of W = 3p + 1 and thus spin-splitting occurs spontaneously.

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Coexistence of Two Types of Spin Splitting Originating from Different Symmetries

Physical Review Letters ◽

10.1103/physrevlett.122.126403 ◽

2019 ◽

Vol 122 (12) ◽

Cited By ~ 4

Author(s):

Koichiro Yaji ◽

Anton Visikovskiy ◽

Takushi Iimori ◽

Kenta Kuroda ◽

Singo Hayashi ◽

...

Keyword(s):

Spin Splitting

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Charge transfer in self-assembled monolayers of molecular conductors containing tripodal anchor and terpyridine-metal redox switching element

Electrochimica Acta ◽

10.1016/j.electacta.2021.138302 ◽

2021 ◽

pp. 138302

Author(s):

Štěpánka Nováková Lachmanová ◽

František Vavrek ◽

Táňa Sebechlebská ◽

Viliam Kolivoška ◽

Michal Valášek ◽

...

Keyword(s):

Charge Transfer ◽

Self Assembled Monolayers ◽

Switching Element ◽

Molecular Conductors ◽

Assembled Monolayers ◽

Self Assembled ◽

Redox Switching ◽

Metal Redox

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Strain Investigation on Spin-Dependent Transport Properties of γ-Graphyne Nanoribbon Between Gold Electrodes

Nanoscale Research Letters ◽

10.1186/s11671-020-03461-3 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Yun Li ◽

Xiaobo Li ◽

Shidong Zhang ◽

Liemao Cao ◽

Fangping Ouyang ◽

...

Keyword(s):

Transport Properties ◽

High Performance ◽

Density Functional ◽

Strain Engineering ◽

Molecular Junctions ◽

Spin Splitting ◽

Functional Theory ◽

Spin Dependent Transport ◽

The Density Functional Theory ◽

Dependent Transport

AbstractStrain engineering has become one of the effective methods to tune the electronic structures of materials, which can be introduced into the molecular junction to induce some unique physical effects. The various γ-graphyne nanoribbons (γ-GYNRs) embedded between gold (Au) electrodes with strain controlling have been designed, involving the calculation of the spin-dependent transport properties by employing the density functional theory. Our calculated results exhibit that the presence of strain has a great effect on transport properties of molecular junctions, which can obviously enhance the coupling between the γ-GYNR and Au electrodes. We find that the current flowing through the strained nanojunction is larger than that of the unstrained one. What is more, the length and strained shape of the γ-GYNR serves as the important factors which affect the transport properties of molecular junctions. Simultaneously, the phenomenon of spin-splitting occurs after introducing strain into nanojunction, implying that strain engineering may be a new means to regulate the electron spin. Our work can provide theoretical basis for designing of high performance graphyne-based devices in the future.

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Old Donors for New Molecular Conductors: Combining TMTSF and BEDT-TTF with Anionic (TaF6)1−x/(PF6)x Alloys

Crystals ◽

10.3390/cryst11040386 ◽

2021 ◽

Vol 11 (4) ◽

pp. 386

Author(s):

Magali Allain ◽

Cécile Mézière ◽

Pascale Auban-Senzier ◽

Narcis Avarvari

Keyword(s):

Single Crystal ◽

Room Temperature ◽

Density Wave ◽

Spin Density Wave ◽

Orthorhombic Phase ◽

Molecular Conductors ◽

Bechgaard Salts ◽

Temperature Conductivity ◽

Room Temperature Conductivity ◽

Resistivity Measurements

Tetramethyl-tetraselenafulvalene (TMTSF) and bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) are flagship precursors in the field of molecular (super)conductors. The electrocrystallization of these donors in the presence of (n-Bu4N)TaF6 or mixtures of (n-Bu4N)TaF6 and (n-Bu4N)PF6 provided Bechgaard salts formulated as (TMTSF)2(TaF6)0.84(PF6)0.16, (TMTSF)2(TaF6)0.56(PF6)0.44, (TMTSF)2(TaF6)0.44(PF6)0.56 and (TMTSF)2(TaF6)0.12(PF6)0.88, together with the monoclinic and orthorhombic phases δm-(BEDT-TTF)2(TaF6)0.94(PF6)0.06 and δo-(BEDT-TTF)2(TaF6)0.43(PF6)0.57, respectively. The use of BEDT-TTF and a mixture of (n-Bu4N)TaF6/TaF5 afforded the 1:1 phase (BEDT-TTF)2(TaF6)2·CH2Cl2. The precise Ta/P ratio in the alloys has been determined by an accurate single crystal X-ray data analysis and was corroborated with solution 19F NMR measurements. In the previously unknown crystalline phase (BEDT-TTF)2(TaF6)2·CH2Cl2 the donors organize in dimers interacting laterally yet no organic-inorganic segregation is observed. Single crystal resistivity measurements on the TMTSF based materials show typical behavior of the Bechgaard phases with room temperature conductivity σ ≈ 100 S/cm and localization below 12 K indicative of a spin density wave transition. The orthorhombic phase δo-(BEDT-TTF)2(TaF6)0.43(PF6)0.57 is semiconducting with the room temperature conductivity estimated to be σ ≈ 0.16–0.5 S/cm while the compound (BEDT-TTF)2(TaF6)2·CH2Cl2 is also a semiconductor, yet with a much lower room temperature conductivity value of 0.001 to 0.0025 S/cm, in agreement with the +1 oxidation state and strong dimerization of the donors.

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Presence of X-Ray Magnetic Circular Dichroism Signal for Zero-Magnetization Antiferromagnetic State

Physical Review Letters ◽

10.1103/physrevlett.126.157402 ◽

2021 ◽

Vol 126 (15) ◽

Author(s):

Norimasa Sasabe ◽

Motoi Kimata ◽

Tetsuya Nakamura

Keyword(s):

Circular Dichroism ◽

Magnetic Circular Dichroism ◽

Antiferromagnetic State ◽

Circular Dichroism Signal ◽

X Ray ◽

Circular Dichroïsm

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Spin–valley Hall phenomena driven by Van Hove singularities in blistered graphene

npj Computational Materials ◽

10.1038/s41524-020-00470-9 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

M. Umar Farooq ◽

Arqum Hashmi ◽

Tomoya Ono ◽

Li Huang

Keyword(s):

First Principles ◽

Opposite Sign ◽

Spin Splitting ◽

First Principles Calculations ◽

Van Hove Singularities ◽

Spin Degree ◽

Hall Effects ◽

Back Scattering ◽

Structural Deformations ◽

Spin Momentum

AbstractUsing first-principles calculations, we investigate the possibility of realizing valley Hall effects (VHE) in blistered graphene sheets. We show that the Van Hove singularities (VHS) induced by structural deformations can give rise to interesting spin–valley Hall phenomena. The broken degeneracy of spin degree of freedom results in spin-filtered VH states and the valley conductivity have a Hall plateau of ±e2/2h, while the blistered structures with time-reversal symmetry show the VHE with the opposite sign of $$\sigma _{xy}^{K/K^{\prime}}$$ σ x y K / K ′ (e2/2h) in the two valleys. Remarkably, these results show that the distinguishable chiral valley pseudospin state can occur even in the presence of VHS induced spin splitting. The robust chiral spin–momentum textures in both massless and massive Dirac cones of the blistered systems indicate significant suppression of carrier back-scattering. Our study provides a different approach to realize spin-filtered and spin-valley contrasting Hall effects in graphene-based devices without any external field.

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Improvements in the profiles and distributions of nitric acid and nitrogen dioxide with the LIMS version 6 dataset

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-4741-2010 ◽

2010 ◽

Vol 10 (10) ◽

pp. 4741-4756 ◽

Cited By ~ 5

Author(s):

E. Remsberg ◽

M. Natarajan ◽

B. T. Marshall ◽

L. L. Gordley ◽

R. E. Thompson ◽

...

Keyword(s):

Nitric Acid ◽

Nitrogen Dioxide ◽

Theoretical Calculations ◽

Spin Splitting ◽

Oxides Of Nitrogen ◽

Polar Night ◽

Chemical Effects ◽

Satellite Sensors ◽

Precision And Accuracy

Abstract. The quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) nitric acid (HNO3) and nitrogen dioxide (NO2) profiles and distributions of 1978/1979 are described after their processing with an updated, Version 6 (V6) algorithm and subsequent archival in 2002. Estimates of the precision and accuracy of both of those species are developed and provided herein. The character of the V6 HNO3 profiles is relatively unchanged from that of the earlier LIMS Version 5 (V5) profiles, except in the upper stratosphere where the interfering effects of CO2 are accounted for better with V6. The accuracy of the retrieved V6 NO2 is also significantly better in the middle and upper stratosphere, due to improvements in its spectral line parameters and in the reduced biases for the accompanying V6 temperature and water vapor profiles. As a result of these important updates, there is better agreement with theoretical calculations for profiles of the HNO3/NO2 ratio, day-to-night NO2 ratio, and with estimates of the production of NO2 in the mesosphere and its descent to the upper stratosphere during polar night. In particular, the findings for middle and upper stratospheric NO2 should also be more compatible with those obtained from more recent satellite sensors because the effects of the spin-splitting of the NO2 lines are accounted for now with the LIMS V6 algorithm. The improved precisions and more frequent retrievals of the LIMS profiles along their orbit tracks provide for better continuity and detail in map analyses of these two species on pressure surfaces. It is judged that the chemical effects of the oxides of nitrogen on ozone can be studied quantitatively throughout the stratosphere with the LIMS V6 data.

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Layer- and gate-tunable spin-orbit coupling in a high-mobility few-layer semiconductor

Science Advances ◽

10.1126/sciadv.abe2892 ◽

2021 ◽

Vol 7 (5) ◽

pp. eabe2892

Author(s):

Dmitry Shcherbakov ◽

Petr Stepanov ◽

Shahriar Memaran ◽

Yaxian Wang ◽

Yan Xin ◽

...

Keyword(s):

Electric Field ◽

High Mobility ◽

Orbit Coupling ◽

Spin Splitting ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Quantum Oscillations ◽

Out Of Plane ◽

Order Of Magnitude ◽

Spin Degeneracy

Spin-orbit coupling (SOC) is a relativistic effect, where an electron moving in an electric field experiences an effective magnetic field in its rest frame. In crystals without inversion symmetry, it lifts the spin degeneracy and leads to many magnetic, spintronic, and topological phenomena and applications. In bulk materials, SOC strength is a constant. Here, we demonstrate SOC and intrinsic spin splitting in atomically thin InSe, which can be modified over a broad range. From quantum oscillations, we establish that the SOC parameter α is thickness dependent; it can be continuously modulated by an out-of-plane electric field, achieving intrinsic spin splitting tunable between 0 and 20 meV. Unexpectedly, α could be enhanced by an order of magnitude in some devices, suggesting that SOC can be further manipulated. Our work highlights the extraordinary tunability of SOC in 2D materials, which can be harnessed for in operando spintronic and topological devices and applications.

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