scholarly journals A mid-infrared biaxial hyperbolic van der Waals crystal

2019 ◽  
Vol 5 (5) ◽  
pp. eaav8690 ◽  
Author(s):  
Zebo Zheng ◽  
Ningsheng Xu ◽  
Stefano L. Oscurato ◽  
Michele Tamagnone ◽  
Fengsheng Sun ◽  
...  
Keyword(s):  
Van Der Waals ◽  
Super Resolution ◽  
Photonic Devices ◽  
Two Dimensional ◽  
New Paradigm ◽  
Mid Infrared ◽  
Guided Modes ◽  
Potential Applications ◽  
Infrared Frequencies ◽  
The Way

Hyperbolic media have attracted much attention in the photonics community due to their ability to confine light to arbitrarily small volumes and their potential applications to super-resolution technologies. The two-dimensional counterparts of these media can be achieved with hyperbolic metasurfaces that support in-plane hyperbolic guided modes upon nanopatterning, which, however, poses notable fabrication challenges and limits the achievable confinement. We show that thin flakes of a van der Waals crystal, α-MoO3, can support naturally in-plane hyperbolic polariton guided modes at mid-infrared frequencies without the need for patterning. This is possible because α-MoO3 is a biaxial hyperbolic crystal with three different Reststrahlen bands, each corresponding to a different crystalline axis. These findings can pave the way toward a new paradigm to manipulate and confine light in planar photonic devices.

scholarly journals Mid infrared polarization engineering via sub-wavelength biaxial hyperbolic van der Waals crystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saurabh Dixit ◽  
Nihar Ranjan Sahoo ◽  
Abhishek Mall ◽  
Anshuman Kumar
Keyword(s):  
Room Temperature ◽  
Extinction Ratio ◽  
Polarization State ◽  
Van Der Waals ◽  
Photonic Devices ◽  
Mid Infrared ◽  
Precise Control ◽  
Electromagnetic Simulations ◽  
Frequency Regime ◽  
Sub Wavelength

AbstractMid-infrared (IR) spectral region is of immense importance for astronomy, medical diagnosis, security and imaging due to the existence of the vibrational modes of many important molecules in this spectral range. Therefore, there is a particular interest in miniaturization and integration of IR optical components. To this end, 2D van der Waals (vdW) crystals have shown great potential owing to their ease of integration with other optoelectronic platforms and room temperature operation. Recently, 2D vdW crystals of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2 \hbox {O}_5$$ V 2 O 5 have been shown to possess the unique phenomenon of natural in-plane biaxial hyperbolicity in the mid-infrared frequency regime at room temperature. Here, we report a unique application of this in-plane hyperbolicity for designing highly efficient, lithography free and extremely subwavelength mid-IR photonic devices for polarization engineering. In particular, we show the possibility of a significant reduction in the device footprint while maintaining an enormous extinction ratio from $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 based mid-IR polarizers. Furthermore, we investigate the application of sub-wavelength thin films of these vdW crystals towards engineering the polarization state of incident mid-IR light via precise control of polarization rotation, ellipticity and relative phase. We explain our results using natural in-plane hyperbolic anisotropy of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 via both analytical and full-wave electromagnetic simulations. This work provides a lithography free alternative for miniaturized mid-infrared photonic devices using the hyperbolic anisotropy of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 .

Tin diselenide van der Waals materials as new candidates for mid-infrared waveguide chips

Nanoscale ◽  
2019 ◽  
Vol 11 (30) ◽  
pp. 14113-14117 ◽  
Author(s):  
Mengfei Xue ◽  
Qi Zheng ◽  
Runkun Chen ◽  
Lihong Bao ◽  
Shixuan Du ◽  
...  
Keyword(s):  
Near Field ◽  
Van Der Waals ◽  
Building Blocks ◽  
Two Dimensional ◽  
Mid Infrared ◽  
Near Field Imaging ◽  
Van Der Waals Materials ◽  
Field Imaging

Near-field imaging of mid-infrared waveguide in SnSe2 slabs promotes two-dimensional van der Waals materials as building blocks for integrated MIR chips.

Two-dimensional layered Janus-In2SeTe/C2N van der Waals heterostructures for photocatalysis and photovoltaics: first-principles calculations

2020 ◽  
Vol 44 (37) ◽  
pp. 16092-16100
Author(s):  
Xiao-Hua Li ◽  
Bao-Ji Wang ◽  
Hui Li ◽  
Xue-Feng Yang ◽  
Rui-Qi Zhao ◽  
...  
Keyword(s):  
Dft Calculations ◽  
First Principles ◽  
Sustainable Energy ◽  
Van Der Waals ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Van Der Waals Heterostructures ◽  
Potential Applications

Through DFT calculations, Janus-In2SeTe/C2N heterostructures are found to have great potential applications in the fields of clean and sustainable energy.

Two-dimensional van der Waals heterojunctions for functional materials and devices

2017 ◽  
Vol 5 (47) ◽  
pp. 12289-12297 ◽  
Author(s):  
Wei Hu ◽  
Jinlong Yang
Keyword(s):  
Electronic Structures ◽  
2D Materials ◽  
Van Der Waals ◽  
Functional Materials ◽  
Two Dimensional ◽  
Potential Applications

Two-dimensional (2D) van der Waals heterojunctions combining the electronic structures of such 2D materials have been predicted theoretically and synthesized experimentally to expect more new properties and potential applications far beyond corresponding 2D materials.

Spin-Constraint Optoelectronic Functionality in Two-Dimensional Ferromagnetic Semiconductor Heterojunctions

2021 ◽  
Author(s):  
Yilv Guo ◽  
Yehui Zhang ◽  
Zhaobo Zhou ◽  
Xiwen Zhang ◽  
Bing Wang ◽  
...  
Keyword(s):  
Van Der Waals ◽  
Optoelectronic Devices ◽  
New Physics ◽  
Ferromagnetic Semiconductor ◽  
Two Dimensional ◽  
Potential Applications ◽  
New Type ◽  
Semiconductor Heterojunctions

Two-dimensional (2D) van der Waals (vdW) engineering has brought about many extraordinary new physics and potential applications. Herein, we propose a new type of spin-constraint optoelectronic devices, implemented in 2D...

scholarly journals The Creation of True Two-Dimensional Silicon Carbide

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1799
Author(s):  
Sakineh Chabi ◽  
Zeynel Guler ◽  
Adrian J. Brearley ◽  
Angelica D. Benavidez ◽  
Ting Shan Luk
Keyword(s):  
Silicon Carbide ◽  
Light Emission ◽  
Van Der Waals ◽  
Longitudinal Optical ◽  
Synthesis Process ◽  
Two Dimensional ◽  
Light Emitting Devices ◽  
Energy Applications ◽  
Successful Isolation ◽  
Potential Applications

This paper reports the successful synthesis of true two-dimensional silicon carbide using a top-down synthesis approach. Theoretical studies have predicted that 2D SiC has a stable planar structure and is a direct band gap semiconducting material. Experimentally, however, the growth of 2D SiC has challenged scientists for decades because bulk silicon carbide is not a van der Waals layered material. Adjacent atoms of SiC bond together via covalent sp3 hybridization, which is much stronger than van der Waals bonding in layered materials. Additionally, bulk SiC exists in more than 250 polytypes, further complicating the synthesis process, and making the selection of the SiC precursor polytype extremely important. This work demonstrates, for the first time, the successful isolation of 2D SiC from hexagonal SiC via a wet exfoliation method. Unlike many other 2D materials such as silicene that suffer from environmental instability, the created 2D SiC nanosheets are environmentally stable, and show no sign of degradation. 2D SiC also shows interesting Raman behavior, different from that of the bulk SiC. Our results suggest a strong correlation between the thickness of the nanosheets and the intensity of the longitudinal optical (LO) Raman mode. Furthermore, the created 2D SiC shows visible-light emission, indicating its potential applications for light-emitting devices and integrated microelectronics circuits. We anticipate that this work will cause disruptive impact across various technological fields, ranging from optoelectronics and spintronics to electronics and energy applications.

scholarly journals Hyperbolic enhancement of photocurrent patterns in minimally twisted bilayer graphene

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
S. S. Sunku ◽  
D. Halbertal ◽  
T. Stauber ◽  
S. Chen ◽  
A. S. McLeod ◽  
...  
Keyword(s):  
Domain Walls ◽  
Hexagonal Boron Nitride ◽  
Twist Angle ◽  
Bilayer Graphene ◽  
Scanning Probe ◽  
Two Dimensional ◽  
Mid Infrared ◽  
Two Dimensional Materials ◽  
Twisted Bilayer Graphene ◽  
Infrared Frequencies

AbstractQuasi-periodic moiré patterns and their effect on electronic properties of twisted bilayer graphene have been intensely studied. At small twist angle θ, due to atomic reconstruction, the moiré superlattice morphs into a network of narrow domain walls separating micron-scale AB and BA stacking regions. We use scanning probe photocurrent imaging to resolve nanoscale variations of the Seebeck coefficient occurring at these domain walls. The observed features become enhanced in a range of mid-infrared frequencies where the hexagonal boron nitride substrate is optically hyperbolic. Our results illustrate the capabilities of the nano-photocurrent technique for probing nanoscale electronic inhomogeneities in two-dimensional materials.

scholarly journals Noncollinear topological textures in two-dimensional van der Waals materials: From magnetic to polar systems

2021 ◽  
pp. 2130004
Author(s):  
Xiaoyan Yao ◽  
Yu Wang ◽  
Shuai Dong
Keyword(s):  
Electric Dipole ◽  
Van Der Waals ◽  
Two Dimensional ◽  
Potential Applications ◽  
Van Der Waals Materials ◽  
Magnetic Skyrmions

In recent years, noncollinear topological textures have long gained increasing research attentions for their high values of both fundamental researches and potential applications. The recent discovery of intrinsic orders in magnetic and polar two-dimensional (2D) van der Waals materials provides a new ideal platform for the investigation of noncollinear topological textures. Here, we review the theoretical and experimental progresses on noncollinear topological textures in 2D van der Waals materials in very recent years. During these years, magnetic skyrmions of both Bloch and Néel types have been observed experimentally in a few 2D van der Waals materials and related heterostructures. Concurrently, more theoretic predictions basing on various mechanisms have been reported about different noncollinear topological textures in 2D van der Waals materials, such as skyrmions, bimerons, anti-biskyrmions and skyrmionium, which are still waiting to be confirmed in experiments. Besides, noncollinear topological electric dipole orders have also been predicted in 2D van der Waals materials. Taking advantage of the intrinsic 2D nature and high integratability, the 2D van der Waals materials will play an important role in the investigation on noncollinear topological textures in both magnetic and polar systems.

scholarly journals A topological quantum optics interface

Science ◽  
2018 ◽  
Vol 359 (6376) ◽  
pp. 666-668 ◽  
Author(s):  
Sabyasachi Barik ◽  
Aziz Karasahin ◽  
Christopher Flower ◽  
Tao Cai ◽  
Hirokazu Miyake ◽  
...  
Keyword(s):  
Quantum Optics ◽  
Photonic Devices ◽  
Edge States ◽  
New Paradigm ◽  
Classical Domain ◽  
Strong Light ◽  
Quantum Emitter ◽  
Topological Quantum ◽  
Potential Applications ◽  
Photonic States

The application of topology in optics has led to a new paradigm in developing photonic devices with robust properties against disorder. Although considerable progress on topological phenomena has been achieved in the classical domain, the realization of strong light-matter coupling in the quantum domain remains unexplored. We demonstrate a strong interface between single quantum emitters and topological photonic states. Our approach creates robust counterpropagating edge states at the boundary of two distinct topological photonic crystals. We demonstrate the chiral emission of a quantum emitter into these modes and establish their robustness against sharp bends. This approach may enable the development of quantum optics devices with built-in protection, with potential applications in quantum simulation and sensing.

Scalable Van der Waals Two-Dimensional PtTe2 Layers Integrated onto Silicon for Efficient Near-to-Mid Infrared Photodetection

2021 ◽  
Author(s):  
Mashiyat Sumaiya Shawkat ◽  
Shihab Bin Hafiz ◽  
Molla Manjurul Islam ◽  
Sohrab Alex Mofid ◽  
Mohammad M. Al Mahfuz ◽  
...  
Keyword(s):  
Van Der Waals ◽  
Two Dimensional ◽  
Mid Infrared ◽  
Infrared Photodetection
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