scholarly journals Optical read-out of Coulomb staircases in a moiré superlattice via trapped interlayer trions

2021 ◽  
Author(s):  
Hyeonjun Baek ◽  
Mauro Brotons-Gisbert ◽  
Aidan Campbell ◽  
Valerio Vitale ◽  
Johannes Lischner ◽  
...  
Keyword(s):  
Optical Probe ◽  
Transition Metal Dichalcogenide ◽  
Interaction Energies ◽  
Coulomb Interactions ◽  
Non Invasive ◽  
Molybdenum Diselenide ◽  
Local Technique ◽  
Non Local ◽  
Coulomb Staircase ◽  
Potential Landscape

AbstractMoiré patterns with a superlattice potential can be formed by vertically stacking two layered materials with a relative twist or lattice constant mismatch. In transition metal dichalcogenide-based systems, the moiré potential landscape can trap interlayer excitons (IXs) at specific atomic registries. Here, we report that spatially isolated trapped IXs in a molybdenum diselenide/tungsten diselenide heterobilayer device provide a sensitive optical probe of carrier filling in their immediate environment. By mapping the spatial positions of individual trapped IXs, we are able to spectrally track the emitters as the moiré lattice is filled with excess carriers. Upon initial doping of the heterobilayer, neutral trapped IXs form charged IXs (IX trions) uniformly with a binding energy of ~7 meV. Upon further doping, the empty superlattice sites sequentially fill, creating a Coulomb staircase: stepwise changes in the IX trion emission energy due to Coulomb interactions with carriers at nearest-neighbour moiré sites. This non-invasive, highly local technique can complement transport and non-local optical sensing techniques to characterize Coulomb interaction energies, visualize charge correlated states, or probe local disorder in a moiré superlattice.

Equilibrium measure for a nonlocal dislocation energy with physical confinement

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Maria Giovanna Mora ◽  
Alessandro Scagliotti
Keyword(s):  
Equilibrium Measure ◽  
Symmetric Case ◽  
Nonlocal Interaction ◽  
Interaction Energies ◽  
Coulomb Interactions ◽  
Positive Edge ◽  
Dislocation Energy ◽  
Explicit Measure ◽  
Edge Dislocations

Abstract In this paper, we characterize the equilibrium measure for a family of nonlocal and anisotropic energies I α I_{\alpha} that describe the interaction of particles confined in an elliptic subset of the plane. The case α = 0 \alpha=0 corresponds to purely Coulomb interactions, while the case α = 1 \alpha=1 describes interactions of positive edge dislocations in the plane. The anisotropy into the energy is tuned by the parameter 𝛼 and favors the alignment of particles. We show that the equilibrium measure is completely unaffected by the anisotropy and always coincides with the optimal distribution in the case α = 0 \alpha=0 of purely Coulomb interactions, which is given by an explicit measure supported on the boundary of the elliptic confining domain. Our result does not seem to agree with the mechanical conjecture that positive edge dislocations at equilibrium tend to arrange themselves along “wall-like” structures. Moreover, this is one of the very few examples of explicit characterization of the equilibrium measure for nonlocal interaction energies outside the radially symmetric case.

scholarly journals Gate-Voltage-Modulated Spin Precession in Graphene/WS2 Field-Effect Transistors

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2879
Author(s):  
Amir Muhammad Afzal ◽  
Muhammad Farooq Khan ◽  
Jonghwa Eom
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Spin Precession ◽  
Orbital Interaction ◽  
Transition Metal Dichalcogenide ◽  
Precession Angle ◽  
Spin Orbital ◽  
Spintronic Devices ◽  
Non Local ◽  
Spin Fet

Transition metal dichalcogenide materials are studied to investigate unexplored research avenues, such as spin transport behavior in 2-dimensional materials due to their strong spin-orbital interaction (SOI) and the proximity effect in van der Waals (vdW) heterostructures. Interfacial interactions between bilayer graphene (BLG) and multilayer tungsten disulfide (ML-WS2) give rise to fascinating properties for the realization of advanced spintronic devices. In this study, a BLG/ML-WS2 vdW heterostructure spin field-effect transistor (FET) was fabricated to demonstrate the gate modulation of Rashba-type SOI and spin precession angle. The gate modulation of Rashba-type SOI and spin precession has been confirmed using the Hanle measurement. The change in spin precession angle agrees well with the local and non-local signals of the BLG/ML-WS2 spin FET. The operation of a spin FET in the absence of a magnetic field at room temperature is successfully demonstrated.

scholarly journals 3D Non-Local Neural Network: A Non-Invasive Biomarker for Immunotherapy Treatment Outcome Prediction. Case-Study: Metastatic Urothelial Carcinoma

2020 ◽  
Vol 6 (12) ◽  
pp. 133
Author(s):  
Francesco Rundo ◽  
Giuseppe Luigi Banna ◽  
Luca Prezzavento ◽  
Francesca Trenta ◽  
Sabrina Conoci ◽  
...  
Keyword(s):  
Urothelial Carcinoma ◽  
Treatment Response ◽  
Ad Hoc ◽  
Non Invasive ◽  
Clinical Dataset ◽  
Average Accuracy ◽  
Response Biomarker ◽  
Metastatic Urothelial Carcinoma ◽  
Non Local

Immunotherapy is regarded as one of the most significant breakthroughs in cancer treatment. Unfortunately, only a small percentage of patients respond properly to the treatment. Moreover, to date, there are no efficient bio-markers able to early discriminate the patients eligible for this treatment. In order to help overcome these limitations, an innovative non-invasive deep pipeline, integrating Computed Tomography (CT) imaging, is investigated for the prediction of a response to immunotherapy treatment. We report preliminary results collected as part of a case study in which we validated the implemented method on a clinical dataset of patients affected by Metastatic Urothelial Carcinoma. The proposed pipeline aims to discriminate patients with high chances of response from those with disease progression. Specifically, the authors propose ad-hoc 3D Deep Networks integrating Self-Attention mechanisms in order to estimate the immunotherapy treatment response from CT-scan images and such hemato-chemical data of the patients. The performance evaluation (average accuracy close to 92%) confirms the effectiveness of the proposed approach as an immunotherapy treatment response biomarker.

Interaction energies of point defects in metals: Non-local effect beyond the LSDA

1997 ◽  
Vol 237-238 ◽  
pp. 361-362 ◽  
Author(s):  
T. Hoshino ◽  
R. Zeller ◽  
P.H. Dederichs ◽  
T. Asada
Keyword(s):  
Point Defects ◽  
Local Effect ◽  
Interaction Energies ◽  
Non Local

scholarly journals Microvascular Damage in a Young Female Archer Assessed by Nailfold Videocapillaroscopy: A Case Report

2020 ◽  
Vol 17 (12) ◽  
pp. 4218 ◽  
Author(s):  
Maria Maddalena Sirufo ◽  
Enrica Maria Bassino ◽  
Francesca De Pietro ◽  
Lia Ginaldi ◽  
Massimo De Martinis
Keyword(s):  
Optical Probe ◽  
Young Female ◽  
Specific Pattern ◽  
Surveillance Program ◽  
Image Analyzer ◽  
Nailfold Videocapillaroscopy ◽  
Microvascular Damage ◽  
Non Invasive ◽  
Microvascular Changes

Archers are known to be exposed to the risk of developing various injuries, including less described microvascular damages, which can however heavily affect the performance of athletes. Nailfold videocapillaroscopy is a safe, proven and non-invasive method that allows us to examine the nail capillaries and diagnose vascular anomalies in athletes suffering from the consequences of microtrauma caused by repeated use of fingertips. The detection of defined capillaroscopic pictures is the basis for the follow-up and suggests carrying out further clinical investigations to exclude underlying pathologies. In women this aspect is even more important since they are more frequently affected by autoimmune diseases such as scleroderma which can cause microcirculation alterations. We report the case of a 16-year-old woman who has been practicing archery for five years. She had been complaining for two years about painful fingertips, worsening in the last year. Through videocapillaroscopy, carried out by using a ×200 optical probe-equipped videocapillaroscope connected to image analyzer software (VideoCap software 3.0; DS Medica, Milan, Italy), we detected changes in the microvasculature compatible with a non-specific pattern. The findings of these anomalies suggest a diagnostic analysis aimed at excluding the presence of systemic diseases such as scleroderma. Once these conditions are excluded, and assuming that the documented alterations are due to the particular muscular effort and vibrations to which the fingers are subjected in shooting, we suggest follow-up to keep under control possible further developments and clinical changes. As far as we know, this is the first report that documents and describes the condition of microvascular changes in an archer. Archers, similar to other athletes who mainly use fingertips such as volleyball players, are more exposed to the development of digital traumas that can induce alterations in the microcirculation. We suggest that a periodic capillaroscopy should be included in the health surveillance program of these athletes, in fact this simple, reliable, non-invasive and inexpensive diagnostic tool is able to recognize early signs of microvascular damage and then suggest indications for further investigations and or follow-up.

scholarly journals Hidden Charge Orders in Low-Dimensional Mott Insulators

2019 ◽  
Vol 9 (4) ◽  
pp. 784
Author(s):  
Serena Fazzini ◽  
Arianna Montorsi
Keyword(s):  
Hubbard Model ◽  
Density Wave ◽  
Finite Size ◽  
Charge Order ◽  
Mott Insulators ◽  
Coulomb Interactions ◽  
Non Local ◽  
Low Dimensional ◽  
A Charge ◽  
Insulating Phase

The opening of a charge gap driven by interaction is a fingerprint of the transition to a Mott insulating phase. In strongly correlated low-dimensional quantum systems, it can be associated to the ordering of hidden non-local operators. For Fermionic 1D models, in the presence of spin–charge separation and short-ranged interaction, a bosonization analysis proves that such operators are the parity and/or string charge operators. In fact, a finite fractional non-local parity charge order is also capable of characterizing some two-dimensional Mott insulators, in both the Fermionic and the bosonic cases. When string charge order takes place in 1D, degenerate edge modes with fractional charge appear, peculiar of a topological insulator. In this article, we review the above framework, and we test it to investigate through density-matrix-renormalization-group (DMRG) numerical analysis the robustness of both hidden orders at half-filling in the 1D Fermionic Hubbard model extended with long range density-density interaction. The preliminary results obtained at finite size including several neighbors in the case of dipolar, screened and unscreened repulsive Coulomb interactions, confirm the phase diagram of the standard extended Hubbard model. Besides the trivial Mott phase, the bond ordered and charge density wave insulating phases are also not destroyed by longer ranged interaction, and still manifest hidden non-local orders.

CVD growth of molybdenum diselenide surface structures with tailored morphology

CrystEngComm ◽  
2018 ◽  
Vol 20 (33) ◽  
pp. 4867-4874 ◽  
Author(s):  
M. Naeem Sial ◽  
Muhammad Usman ◽  
Binjie Zheng ◽  
Yanan Yu ◽  
Andraž Mavrič ◽  
...  
Keyword(s):  
Transition Metal ◽  
Silicon Substrate ◽  
Atmospheric Pressure ◽  
Surface Structures ◽  
Native Oxide ◽  
Transition Metal Dichalcogenide ◽  
Native Oxide Layer ◽  
Molybdenum Diselenide ◽  
Cvd Growth ◽  
Tunable Morphology

Controllable atmospheric pressure CVD has been optimized to grow transition metal dichalcogenide MoSe2 with tunable morphology at 750 °C on a silicon substrate with a native oxide layer of 250 nm.

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