Enhanced magneto-optical response due to the flat band in nanoribbons made from the α−T3 lattice

2019 ◽  
Vol 99 (4) ◽  
Author(s):  
Yan-Ru Chen ◽  
Yong Xu ◽  
Jun Wang ◽  
Jun-Feng Liu ◽  
Zhongshui Ma
Keyword(s):  
Optical Response ◽  
Flat Band

scholarly journals Optical signatures of multifold fermions in the chiral topological semimetal CoSi

2020 ◽  
Vol 117 (44) ◽  
pp. 27104-27110 ◽  
Author(s):  
Bing Xu ◽  
Zhenyao Fang ◽  
Miguel-Ángel Sánchez-Martínez ◽  
Jorn W. F. Venderbos ◽  
Zhuoliang Ni ◽  
...  
Keyword(s):  
Optical Conductivity ◽  
Chemical Potential ◽  
Tight Binding ◽  
Low Frequency ◽  
Optical Response ◽  
Flat Band ◽  
Fermi Velocity ◽  
Topological Semimetal ◽  
Different Types ◽  
Topological Semimetals

We report the optical conductivity in high-quality crystals of the chiral topological semimetal CoSi, which hosts exotic quasiparticles known as multifold fermions. We find that the optical response is separated into several distinct regions as a function of frequency, each dominated by different types of quasiparticles. The low-frequency intraband response is captured by a narrow Drude peak from a high-mobility electron pocket of double Weyl quasiparticles, and the temperature dependence of the spectral weight is consistent with its Fermi velocity. By subtracting the low-frequency sharp Drude and phonon peaks at low temperatures, we reveal two intermediate quasilinear interband contributions separated by a kink at 0.2 eV. Using Wannier tight-binding models based on first-principle calculations, we link the optical conductivity above and below 0.2 eV to interband transitions near the double Weyl fermion and a threefold fermion, respectively. We analyze and determine the chemical potential relative to the energy of the threefold fermion, revealing the importance of transitions between a linearly dispersing band and a flat band. More strikingly, below 0.1 eV our data are best explained if spin-orbit coupling is included, suggesting that at these energies, the optical response is governed by transitions between a previously unobserved fourfold spin-3/2 node and a Weyl node. Our comprehensive combined experimental and theoretical study provides a way to resolve different types of multifold fermions in CoSi at different energy. More broadly, our results provide the necessary basis to interpret the burgeoning set of optical and transport experiments in chiral topological semimetals.

The geometric structure and optical response of gaseous endohedral magnesium-fullerenes

2003 ◽  
Vol 50 (15-17) ◽  
pp. 2691-2704 ◽  
Author(s):  
M. Aichinger ◽  
S. A. Chin ◽  
E. Krotscheck ◽  
H. A. Schuessler
Keyword(s):  
Geometric Structure ◽  
Optical Response

A New Method of Viscosity Determination from the Electro-Optical Response of a Nematic LCD

1996 ◽  
Vol 6 (12) ◽  
pp. 1663-1668 ◽  
Author(s):  
O. Cossalter ◽  
B. Cramer ◽  
D. A. Mlynski
Keyword(s):  
Optical Response ◽  
New Method ◽  
Viscosity Determination

Analyzing the interface trap density in SiGe capacitors using an abnormal flat band voltage shift at low temperature

2020 ◽  
Vol 13 (11) ◽  
pp. 111006
Author(s):  
Li-Chuan Sun ◽  
Chih-Yang Lin ◽  
Po-Hsun Chen ◽  
Tsung-Ming Tsai ◽  
Kuan-Ju Zhou ◽  
...  
Keyword(s):  
Low Temperature ◽  
Trap Density ◽  
Flat Band ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Flat Band Voltage ◽  
Voltage Shift

A New Fluorescent Salen-uranyl Sensor for the Sub-ppm Detection of Chemical Warfare Agents

2020 ◽  
Vol 24 (20) ◽  
pp. 2378-2382
Author(s):  
Andrea Pappalardo ◽  
Chiara M.A. Gangemi ◽  
Rosa Maria Toscano ◽  
Giuseppe Trusso Sfrazzetto
Keyword(s):  
Real Time ◽  
Fluorescent Sensor ◽  
Chemical Warfare Agents ◽  
Optical Response ◽  
Chemical Warfare ◽  
Lethal Effects ◽  
Strong Affinity ◽  
Chemical Attack ◽  
Fluorescence Measurements ◽  
Warfare Agents

Real-time sensing of Chemical Warfare Agents (CWAs) is today a crucial topic to prevent the lethal effects of a terroristic chemical attack. For this reason, the development of efficient, selective, sensitive and reversible sensoristic devices, able to detect by optical response ppm levels of these compounds, is strongly required. Here, the synthesis of a new fluorescent sensor based on a salen-uranyl scaffold, functionalized with two bodipy moieties, and its application for the detection of sub-ppm levels of CWAs is reported. Detection properties were evaluated by fluorescence measurements and selectivity tests demonstrated the strong affinity for CWAs.

Optical Response of a Sphere Coupled to a Metal Substrate

1987 ◽  
Vol 56 (4) ◽  
pp. 1587-1602 ◽  
Author(s):  
Tadashi Takemori ◽  
Masahiro Inoue ◽  
Kazuo Ohtaka
Keyword(s):  
Optical Response ◽  
Metal Substrate

scholarly journals Silicon Carbide-Gated Nanofluidic Membrane for Active Control of Electrokinetic Ionic Transport

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 535
Author(s):  
Antonia Silvestri ◽  
Nicola Di Trani ◽  
Giancarlo Canavese ◽  
Paolo Motto Ros ◽  
Leonardo Iannucci ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Silicon Carbide ◽  
Power Consumption ◽  
Low Power ◽  
Electrochemical Impedance ◽  
Field Effect Transistors ◽  
External Control ◽  
Low Power Consumption ◽  
Flat Band ◽  
Ionic Field

Manipulation of ions and molecules by external control at the nanoscale is highly relevant to biomedical applications. We report a biocompatible electrode-embedded nanofluidic channel membrane designed for electrofluidic applications such as ionic field-effect transistors for implantable drug-delivery systems. Our nanofluidic membrane includes a polysilicon electrode electrically isolated by amorphous silicon carbide (a-SiC). The nanochannel gating performance was experimentally investigated based on the current-voltage (I-V) characteristics, leakage current, and power consumption in potassium chloride (KCl) electrolyte. We observed significant modulation of ionic diffusive transport of both positively and negatively charged ions under physical confinement of nanochannels, with low power consumption. To study the physical mechanism associated with the gating performance, we performed electrochemical impedance spectroscopy. The results showed that the flat band voltage and density of states were significantly low. In light of its remarkable performance in terms of ionic modulation and low power consumption, this new biocompatible nanofluidic membrane could lead to a new class of silicon implantable nanofluidic systems for tunable drug delivery and personalized medicine.

scholarly journals Gap generation and flat band catalysis in dice model with local interaction

2021 ◽  
Vol 103 (15) ◽  
Author(s):  
E. V. Gorbar ◽  
V. P. Gusynin ◽  
D. O. Oriekhov
Keyword(s):  
Local Interaction ◽  
Flat Band ◽  
Dice Model
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