scholarly journals Magic angle and plasmon mode engineering in twisted trilayer graphene with pressure

2021 ◽  
Vol 104 (20) ◽  
Author(s):  
Zewen Wu ◽  
Xueheng Kuang ◽  
Zhen Zhan ◽  
Shengjun Yuan
Keyword(s):  
Plasmon Mode ◽  
Magic Angle ◽  
Trilayer Graphene

scholarly journals Electric field–tunable superconductivity in alternating-twist magic-angle trilayer graphene

Science ◽  
2021 ◽  
Vol 371 (6534) ◽  
pp. 1133-1138 ◽  
Author(s):  
Zeyu Hao ◽  
A. M. Zimmerman ◽  
Patrick Ledwith ◽  
Eslam Khalaf ◽  
Danial Haie Najafabadi ◽  
...  
Keyword(s):  
Displacement Field ◽  
Weak Coupling ◽  
Twist Angle ◽  
Magic Angle ◽  
Van Hove Singularity ◽  
Displacement Fields ◽  
Graphene Layers ◽  
Vdw Heterostructure ◽  
Quantum Phenomena ◽  
Trilayer Graphene

Engineering moiré superlattices by twisting layers in van der Waals (vdW) heterostructures has uncovered a wide array of quantum phenomena. We constructed a vdW heterostructure that consists of three graphene layers stacked with alternating twist angles ±θ. At the average twist angle θ ~ 1.56°, a theoretically predicted “magic angle” for the formation of flat electron bands, we observed displacement field–tunable superconductivity with a maximum critical temperature of 2.1 kelvin. By tuning the doping level and displacement field, we found that superconducting regimes occur in conjunction with flavor polarization of moiré bands and are bounded by a van Hove singularity (vHS) at high displacement fields. Our findings display inconsistencies with a weak coupling description, suggesting that the observed moiré superconductivity has an unconventional nature.

scholarly journals Tunable strongly coupled superconductivity in magic-angle twisted trilayer graphene

Nature ◽  
2021 ◽  
Vol 590 (7845) ◽  
pp. 249-255
Author(s):  
Jeong Min Park ◽  
Yuan Cao ◽  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
Pablo Jarillo-Herrero
Keyword(s):  
Magic Angle ◽  
Strongly Coupled ◽  
Trilayer Graphene

scholarly journals Flat bands, electron interactions, and magnetic order in magic-angle mono-trilayer graphene

2021 ◽  
Vol 5 (8) ◽  
Author(s):  
Zachary A. H. Goodwin ◽  
Lennart Klebl ◽  
Valerio Vitale ◽  
Xia Liang ◽  
Vivek Gogtay ◽  
...  
Keyword(s):  
Magnetic Order ◽  
Magic Angle ◽  
Flat Bands ◽  
Trilayer Graphene ◽  
Electron Interactions

Enhanced-Fluorescence of a Dye on DNA- assembled Gold Nano-Dimers Discriminated by Lifetime Correlation Spectroscopy

2017 ◽  
Author(s):  
Pedro M. R. Paulo ◽  
David Botequim ◽  
Agnieszka Jóskowiak ◽  
Sofia Martins ◽  
Duarte M. F. Prazeres ◽  
...  
Keyword(s):  
Single Molecule ◽  
Fluorescence Emission ◽  
Directed Assembly ◽  
Plasmon Mode ◽  
Correlation Spectroscopy ◽  
Enhanced Fluorescence ◽  
Detection Volume ◽  
Relaxation Component ◽  
Good Agreement ◽  
Confocal Detection

<div> <div> <div> <p>We have employed DNA-directed assembly to prepare dimers of gold nanoparticles and used their longitudinally coupled plasmon mode to enhance the fluorescence emission of an organic red-emitting dye, Atto-655. The plasmon- enhanced fluorescence of this dye using dimers of 80 nm particles was measured at single molecule detection level. The top enhancement factors were above 1000-fold in 71% of the dimers within a total of 32 dimers measured, and, in some cases, they reached almost 4000-fold, in good agreement with model simulations. Additionally, fluorescence lifetime correlation analysis enabled the separation of enhanced from non-enhanced emission simultaneously collected in our confocal detection volume. This approach allowed us to recover a short relaxation component exclusive to enhanced emission that is attributed to the interaction of the dye with DNA in the interparticle gaps. </p> </div> </div> </div>

Pulse Shaped Dynamic Nuclear Polarization Under Magic Angle Spinning

2019 ◽  
Author(s):  
ASIF EQUBAL ◽  
Kan Tagami ◽  
Songi Han
Keyword(s):  
Electron Spin ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Total Electron ◽  
Spin Lattice ◽  
Maximum Benefit ◽  
Selective Saturation ◽  
Angle Spinning

In this paper, we report on an entirely novel way of improving the MAS-DNP efficiency by shaped μw pulse train irradiation for fast and broad-banded (FAB) saturation of the electron spin resonance. FAB-DNP achieved with Arbitrary Wave Generated shaped μw pulse trains facilitates effective and selective saturation of a defined fraction of the total electron spins, and provides superior control over the DNP efficiency under MAS. Experimental and quantum-mechanics based numerically simulated results together demonstrate that FAB-DNP significantly outperforms CW-DNP when the EPR-line of PAs is broadened by conformational distribution and exchange coupling. We demonstrate that the maximum benefit of FAB DNP is achieved when the electron spin-lattice relaxation is fast relative to the MAS frequency, i.e. at higher temperatures and/or when employing metals as PAs. Calculations predict that under short T<sub>1e </sub>conditions AWG-DNP can achieve as much as ~4-fold greater enhancement compared to CW-DNP.

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