Vibronic response of a spin-1/2 state from a carbon impurity in two-dimensional WS2

Abstract We demonstrate the creation of a spin-1/2 state via the atomically controlled generation of magnetic carbon radical ions (CRIs) in synthetic two-dimensional transition metal dichalcogenides. Hydrogenated carbon impurities located at chalcogen sites introduced by chemical doping are activated with atomic precision by hydrogen depassivation using a scanning probe tip. In its anionic state, the carbon impurity exhibits a magnetic moment of 1 μB resulting from an unpaired electron populating a spin-polarized in-gap orbital. By inelastic tunneling spectroscopy and density functional theory we show that the CRI defect states couple to a small number of vibrational modes, including a local, breathing-type mode. The electron-phonon coupling strength critically depends on the spin state and differs for monolayer and bilayer WS2. These carbon radical ions in TMDs comprise a new class of surface-bound, single-atom spin-qubits that can be selectively introduced, are spatially precise, feature a well-understood vibronic spectrum, and are charge state controlled.

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Spin-dependent vibronic response of a carbon radical ion in two-dimensional WS2

Nature Communications ◽

10.1038/s41467-021-27585-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Katherine A. Cochrane ◽

Jun-Ho Lee ◽

Christoph Kastl ◽

Jonah B. Haber ◽

Tianyi Zhang ◽

...

Keyword(s):

Transition Metal Dichalcogenides ◽

Chemical Doping ◽

Two Dimensional ◽

Defect States ◽

Effective Spin ◽

Carbon Impurity ◽

Atomic Spin ◽

Carbon Impurities ◽

Spin Polarized ◽

Metal Dichalcogenides

AbstractAtomic spin centers in 2D materials are a highly anticipated building block for quantum technologies. Here, we demonstrate the creation of an effective spin-1/2 system via the atomically controlled generation of magnetic carbon radical ions (CRIs) in synthetic two-dimensional transition metal dichalcogenides. Hydrogenated carbon impurities located at chalcogen sites introduced by chemical doping are activated with atomic precision by hydrogen depassivation using a scanning probe tip. In its anionic state, the carbon impurity is computed to have a magnetic moment of 1 μB resulting from an unpaired electron populating a spin-polarized in-gap orbital. We show that the CRI defect states couple to a small number of local vibrational modes. The vibronic coupling strength critically depends on the spin state and differs for monolayer and bilayer WS2. The carbon radical ion is a surface-bound atomic defect that can be selectively introduced, features a well-understood vibronic spectrum, and is charge state controlled.

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Metal Dichalcogenide Nanomeshes: Structural, Electronic and Magnetic Properties

Physical Chemistry Chemical Physics ◽

10.1039/d1cp03743a ◽

2021 ◽

Author(s):

Mohamed Helal ◽

H. M. El-Sayed ◽

Ahmed A Maarouf ◽

Mohamed Fadlallah

Keyword(s):

Density Functional Theory ◽

Magnetic Properties ◽

Transition Metal ◽

Structural Stability ◽

Density Functional ◽

Transition Metal Dichalcogenides ◽

Two Dimensional ◽

Functional Theory ◽

Electronic And Magnetic Properties ◽

Metal Dichalcogenides

Motivated by the successful preparation of two-dimensional transition metal dichalcogenides (2D- TMDs) nanomeshes in the last three years, we use density functional theory (DFT) to study the structural stability, mechanical,...

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Excitons in two-dimensional atomic layer materials from time-dependent density functional theory: mono-layer and bi-layer hexagonal boron nitride and transition-metal dichalcogenides

Physical Chemistry Chemical Physics ◽

10.1039/c9cp06034k ◽

2020 ◽

Vol 22 (5) ◽

pp. 2908-2916 ◽

Cited By ~ 1

Author(s):

Yasumitsu Suzuki ◽

Kazuyuki Watanabe

Keyword(s):

Density Functional ◽

Hexagonal Boron Nitride ◽

Transition Metal Dichalcogenides ◽

Atomic Layer ◽

Time Dependent ◽

Two Dimensional ◽

Functional Theory ◽

Mono Layer ◽

Metal Dichalcogenides ◽

Dependent Density

Time-dependent density functional theory has been applied to the calculation of absorption spectra for two dimensional atomic layer materials: mono-layer and bi-layer hexagonal boron nitride and mono-layer transition metal dichalcogenides.

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Deep Learning Enabled Strain Mapping of Single-Atom Defects in Two-Dimensional Transition Metal Dichalcogenides with Sub-Picometer Precision

Nano Letters ◽

10.1021/acs.nanolett.0c00269 ◽

2020 ◽

Vol 20 (5) ◽

pp. 3369-3377 ◽

Cited By ~ 3

Author(s):

Chia-Hao Lee ◽

Abid Khan ◽

Di Luo ◽

Tatiane P. Santos ◽

Chuqiao Shi ◽

...

Keyword(s):

Deep Learning ◽

Transition Metal ◽

Transition Metal Dichalcogenides ◽

Single Atom ◽

Two Dimensional ◽

Strain Mapping ◽

Metal Dichalcogenides

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Molecular Adsorption of NH3 and NO2 on Zr and Hf Dichalcogenides (S, Se, Te) Monolayers: A Density Functional Theory Study

Nanomaterials ◽

10.3390/nano10061215 ◽

2020 ◽

Vol 10 (6) ◽

pp. 1215

Author(s):

Shimeles Shumi Raya ◽

Abu Saad Ansari ◽

Bonggeun Shong

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Transition Metal Dichalcogenides ◽

Dielectric Materials ◽

Molecular Adsorption ◽

Two Dimensional ◽

Functional Theory ◽

Molecular Adsorbates ◽

Semiconducting Properties ◽

Metal Dichalcogenides

Due to their atomic thicknesses and semiconducting properties, two-dimensional transition metal dichalcogenides (TMDCs) are gaining increasing research interest. Among them, Hf- and Zr-based TMDCs demonstrate the unique advantage that their oxides (HfO2 and ZrO2) are excellent dielectric materials. One possible method to precisely tune the material properties of two-dimensional atomically thin nanomaterials is to adsorb molecules on their surfaces as non-bonded dopants. In the present work, the molecular adsorption of NO2 and NH3 on the two-dimensional trigonal prismatic (1H) and octahedral (1T) phases of Hf and Zr dichalcogenides (S, Se, Te) is studied using dispersion-corrected periodic density functional theory (DFT) calculations. The adsorption configuration, energy, and charge-transfer properties during molecular adsorption are investigated. In addition, the effects of the molecular dopants (NH3 and NO2) on the electronic structure of the materials are studied. It was observed that the adsorbed NH3 donates electrons to the conduction band of the Hf (Zr) dichalcogenides, while NO2 receives electrons from the valance band. Furthermore, the NO2 dopant affects than NH3 significantly. The resulting band structure of the molecularly doped Zr and Hf dichalcogenides are modulated by the molecular adsorbates. This study explores, not only the properties of the two-dimensional 1H and 1T phases of Hf and Zr dichalcogenides (S, Se, Te), but also tunes their electronic properties by adsorbing non-bonded dopants.

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Single-atom doping of MoS2 with manganese enables ultrasensitive detection of dopamine: Experimental and computational approach

Science Advances ◽

10.1126/sciadv.abc4250 ◽

2020 ◽

Vol 6 (32) ◽

pp. eabc4250 ◽

Cited By ~ 6

Author(s):

Yu Lei ◽

Derrick Butler ◽

Michael C. Lucking ◽

Fu Zhang ◽

Tunan Xia ◽

...

Keyword(s):

Density Functional ◽

Transition Metal Dichalcogenides ◽

Density Functional Theory Calculations ◽

Single Atom ◽

Buffer Solution ◽

Dopamine Detection ◽

Transmission Electron ◽

Scanning Transmission ◽

Metal Dichalcogenides ◽

Metal Doped

Two-dimensional transition metal dichalcogenides (TMDs) emerged as a promising platform to construct sensitive biosensors. We report an ultrasensitive electrochemical dopamine sensor based on manganese-doped MoS2 synthesized via a scalable two-step approach (with Mn ~2.15 atomic %). Selective dopamine detection is achieved with a detection limit of 50 pM in buffer solution, 5 nM in 10% serum, and 50 nM in artificial sweat. Density functional theory calculations and scanning transmission electron microscopy show that two types of Mn defects are dominant: Mn on top of a Mo atom (MntopMo) and Mn substituting a Mo atom (MnMo). At low dopamine concentrations, physisorption on MnMo dominates. At higher concentrations, dopamine chemisorbs on MntopMo, which is consistent with calculations of the dopamine binding energy (2.91 eV for MntopMo versus 0.65 eV for MnMo). Our results demonstrate that metal-doped layered materials, such as TMDs, constitute an emergent platform to construct ultrasensitive and tunable biosensors.

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Interfacial properties of borophene contacts with two-dimensional semiconductors

Physical Chemistry Chemical Physics ◽

10.1039/c7cp04570k ◽

2017 ◽

Vol 19 (35) ◽

pp. 23982-23989 ◽

Cited By ~ 17

Author(s):

Jie Yang ◽

Ruge Quhe ◽

Shenyan Feng ◽

Qiaoxuan Zhang ◽

Ming Lei ◽

...

Keyword(s):

Density Functional ◽

Transition Metal Dichalcogenides ◽

Dft Method ◽

Interfacial Properties ◽

Group Iv ◽

Two Dimensional ◽

Functional Theory ◽

Group V ◽

Two Dimensional Materials ◽

Metal Dichalcogenides

Interfacial properties of β12phase borophene contacts with other common two-dimensional materials (transition-metal dichalcogenides, group IV-enes and group V-enes) have been systematically studied using a density functional theory (DFT) method.

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Tunable Single-Atomic Charge/Spin States of Intercalant Co Ions in a Transition Metal Dichalcogenide

10.21203/rs.3.rs-647929/v1 ◽

2021 ◽

Author(s):

Seongjoon Lim ◽

Shangke Pan ◽

Kefeng Wang ◽

Alexey Ushakov ◽

Ekaterina Sukhanova ◽

...

Keyword(s):

Transition Metal ◽

Scanning Probe Microscopy ◽

Density Functional ◽

2D Materials ◽

Transition Metal Dichalcogenides ◽

Atomic Charge ◽

Single Atom ◽

Transition Metal Dichalcogenide ◽

Functional Theory ◽

Metal Dichalcogenides

Abstract Intercalation raises manifold possibilities to manipulate the properties of two-dimensional (2D) materials1, and its impact on local electronic/magnetic properties has drawn much attention with the rise of nano-structured 2D materials2,3. Typically, changing an ionic state in a solid involves a dramatic local change of energy as well as orbital/spin magnetic moment from its ground state. However, the atomic investigation of the charging process of an intercalant ion in 2D material has never been explored while such subject has been studied in artificially deposited atoms on thin insulating 2D layers using scanning probe microscopy4–7. Herein, we demonstrate an atomical manipulation of the charge and spin state of Co ions on a metallic NbS2, obtained by cleaving of Co-intercalated NbS2. Density functional theory investigation of various Co configurations reveals that the charging is possible due to a change in the crystal field at the surface and a significant coupling between NbS2 and intercalants occurs via orbitals of the a1g symmetry. The results can be generalized to numerous other combinations of intercalants and base matrixes, suggesting that intercalated transition metal dichalcogenides can be a new platform to introduce single-atom operation 2D electronics/spintronics.

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Insight into the Anchoring Effect of Two-Dimensional TiX2 (X = S, Se, Te) Materials for Lithium-Sulfur Batteries: A DFT Study

Journal of The Electrochemical Society ◽

10.1149/1945-7111/ac3ab2 ◽

2021 ◽

Author(s):

Qiao Wu ◽

Yuchao Chen ◽

Xiaoqian Hao ◽

Tianjiao Zhu ◽

Yongan Cao ◽

...

Keyword(s):

Density Functional ◽

Transition Metal Dichalcogenides ◽

Discharge Process ◽

Two Dimensional ◽

Functional Theory ◽

Anchoring Effect ◽

Adsorption Behaviors ◽

Lithium Sulfur Batteries ◽

Metal Dichalcogenides ◽

Lithium Sulfur

Abstract It is desirable to develop suitable anchoring materials to restrain the notorious shuttle phenomenon in lithium-sulfur (Li-S) batteries. Two-dimensional transition metal dichalcogenides (2D TMDs), especially TiS2, with excellent physicochemical properties have attracted much attention. Here, density functional theory (DFT) computations were performed to systematically explore the adsorption behaviors of lithium polysulfides (LiPSs) over TiX2 (X = S, Se, Te) monolayer. It is concluded that TiS2 shows the best anchoring effect owing to the strongest adsorption energy, and the intrinsic structures of LiPSs after adsorption could be preserved by calculating the decomposition energy. Moreover, the low diffusion energy barrier of Li2S on TiS2 surface is expected to accelerate the kinetics during the charge/discharge process. Based on a series of calculations and discussion, we can theoretically demonstrate that TiS2, as an anchoring material, has advantages over TiSe2 and TiTe2 in enhancing Li-S batteries performance.

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