Integration of single photon emitters in 2D layered materials with a silicon nitride photonic chip

Abstract Photonic integrated circuits (PICs) enable the miniaturization of optical quantum circuits because several optic and electronic functionalities can be added on the same chip. Integrated single photon emitters (SPEs) are central building blocks for such quantum photonic circuits. SPEs embedded in 2D transition metal dichalcogenides have some unique properties that make them particularly appealing for large-scale integration. Here we report on the integration of a WSe2 monolayer onto a Silicon Nitride (SiN) chip. We demonstrate the coupling of SPEs with the guided mode of a SiN waveguide and study how the on-chip single photon extraction can be maximized by interfacing the 2D-SPE with an integrated dielectric cavity. Our approach allows the use of optimized PIC platforms without the need for additional processing in the SPE host material. In combination with improved wafer-scale CVD growth of 2D materials, this approach provides a promising route towards scalable quantum photonic chips.

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Site-Controlled Telecom Single-Photon Emitters in Atomically-thin MoTe2

10.21203/rs.3.rs-452814/v1 ◽

2021 ◽

Author(s):

Huan Zhao ◽

Michael Pettes ◽

Yu Zheng ◽

Han Htoon

Keyword(s):

Single Photon ◽

Transition Metal Dichalcogenides ◽

Zeeman Splitting ◽

Single Photons ◽

Layer By Layer ◽

Single Photon Emitters ◽

Anisotropic Exchange Interaction ◽

Pillar Arrays ◽

Linearly Polarized ◽

Metal Dichalcogenides

Abstract Quantum emitters (QEs) in two-dimensional transition metal dichalcogenides (2D TMDCs) have advanced to the forefront of quantum communication and transduction research1 due to their unique potentials in accessing valley pseudo-spin degree of freedom (DOF)2 and facile integration into quantum-photonic, electronic and sensing platforms via the layer-by-layer-assembly approach.3 To date, QEs capable of operating in O-C telecommunication bands have not been demonstrated in TMDCs.4-7 Here we report a deterministic creation of such telecom QEs emitting over the 1080 to 1550 nm wavelength range via coupling of 2D molybdenum ditelluride (MoTe2) to strain inducing nano-pillar arrays.8,9 Our Hanbury Brown and Twiss experiment conducted at 10 K reveals clear photon antibunching with 90% single photon purity. Ultra-long lifetimes, 4-6 orders of magnitude longer than that of the 2D exciton, are also observed. Polarization analysis further reveals that while some QEs display cross-linearly polarized doublets with ~1 meV splitting resulting from the strain induced anisotropic exchange interaction, valley degeneracy is preserved in other QEs. Valley Zeeman splitting as well as restoring of valley symmetry in cross-polarized doublets are observed under 8T magnetic field. In contrast to other telecom QEs,10-12 our QEs which offer the potential to access valley DOF through single photons, could lead to unprecedented advantages in optical fiber-based quantum networks.

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Exciton-dielectric mode coupling in MoS2 nanoflakes visualized by cathodoluminescence

Nanophotonics ◽

10.1515/nanoph-2021-0643 ◽

2022 ◽

Vol 0 (0) ◽

Author(s):

Dung Thi Vu ◽

Nikolaos Matthaiakakis ◽

Hikaru Saito ◽

Takumi Sannomiya

Keyword(s):

Light Emission ◽

Single Photon ◽

Transition Metal Dichalcogenides ◽

High Refractive Index ◽

Scanning Transmission Electron Microscope ◽

Optical Responses ◽

Single Photon Emitters ◽

Scanning Transmission ◽

Metal Dichalcogenides ◽

Energy Conversion Devices

Abstract Two-dimensional (2D) transition metal dichalcogenides (TMDCs), possessing unique exciton luminescence properties, have attracted significant attention for use in optical and electrical devices. TMDCs are also high refractive index materials that can strongly confine the electromagnetic field in nanoscale dimensions when patterned into nanostructures, thus resulting in complex light emission that includes exciton and dielectric resonances. Here, we use cathodoluminescence (CL) to experimentally visualize the emission modes of single molybdenum disulfide (MoS2) nanoflakes and to investigate luminescence enhancement due to dielectric resonances in nanoscale dimensions, by using a scanning transmission electron microscope. Specifically, we identify dielectric modes whose resonant wavelength is sensitive to the shape and size of the nanoflake, and exciton emission peaks whose energies are insensitive to the geometry of the flakes. Using a four-dimensional CL method and boundary element method simulations, we further theoretically and experimentally visualize the emission polarization and angular emission patterns, revealing the coupling of the exciton and dielectric resonant modes. Such nanoscopic observation provides a detailed understanding of the optical responses of MoS2 including modal couplings of excitons and dielectric resonances which play a crucial role in the development of energy conversion devices, single-photon emitters, and nanophotonic circuits with enhanced light-matter interactions.

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Optical properties of atomically thin transition metal dichalcogenides: observations and puzzles

Nanophotonics ◽

10.1515/nanoph-2016-0165 ◽

2017 ◽

Vol 6 (6) ◽

pp. 1289-1308 ◽

Cited By ~ 89

Author(s):

Maciej Koperski ◽

Maciej R. Molas ◽

Ashish Arora ◽

Karol Nogajewski ◽

Artur O. Slobodeniuk ◽

...

Keyword(s):

Optical Properties ◽

Transition Metal ◽

Optical Pumping ◽

Single Photon ◽

Hexagonal Boron Nitride ◽

Transition Metal Dichalcogenides ◽

Wide Band ◽

Open Questions ◽

Single Photon Emitters ◽

Metal Dichalcogenides

AbstractRecent results on the optical properties of monolayer and few layers of semiconducting transition metal dichalcogenides are reviewed. Experimental observations are presented and discussed in the frame of existing models, highlighting the limits of our understanding in this emerging field of research. We first introduce the representative band structure of these systems and their interband optical transitions. The effect of an external magnetic field is then considered to discuss Zeeman spectroscopy and optical pumping experiments, both revealing phenomena related to the valley degree of freedom. Finally, we discuss the observation of single photon emitters in different types of layered materials, including wide band gap hexagonal boron nitride. While going through these topics, we try to focus on open questions and on experimental observations, which do not yet have a clear explanation.

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Site-Controlled Telecom Single-Photon Emitters in Atomically-thin MoTe2

10.21203/rs.3.rs-452814/v2 ◽

2021 ◽

Author(s):

Huan Zhao ◽

Micahel Pettes ◽

Yu Zheng ◽

Han Htoon

Keyword(s):

Single Photon ◽

Transition Metal Dichalcogenides ◽

Zeeman Splitting ◽

Liquid Nitrogen Temperature ◽

Single Photon Emitters ◽

Anisotropic Exchange Interaction ◽

Pillar Arrays ◽

Anisotropic Exchange ◽

Linearly Polarized ◽

Metal Dichalcogenides

Abstract Quantum emitters (QEs) in two-dimensional transition metal dichalcogenides (2D TMDCs) have advanced to the forefront of quantum communication and transduction research1. To date, QEs capable of operating in O-C telecommunication bands have not been demonstrated in TMDCs.2-5 Here we report a deterministic creation of such telecom QEs emitting over the 1080 to 1550 nm wavelength range via coupling of 2D molybdenum ditelluride (MoTe2) to strain inducing nano-pillar arrays.6, 7 Our Hanbury Brown and Twiss experiment conducted at 10 K reveals clear photon antibunching with 90% single photon purity. The photon antibuching can be observed up to liquid nitrogen temperature (77 K). Polarization analysis further reveals that while some QEs display cross-linearly polarized doublets with ~1 meV splitting resulting from the strain induced anisotropic exchange interaction, valley degeneracy is preserved in other QEs. Valley Zeeman splitting as well as restoring of valley symmetry in cross-polarized doublets are observed under 8T magnetic field.

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Timing Optimization During the Physical Synthesis of Cell-Based VLSI Circuits

10.5753/ctd.2017.3465 ◽

2017 ◽

Author(s):

Vinícius Dos Santos Livramento ◽

José Luís Güntzel

Keyword(s):

Integrated Circuits ◽

Large Scale ◽

Cmos Technology ◽

Vlsi Circuits ◽

Consumer Electronics ◽

Clock Frequency ◽

Wide Range ◽

Large Scale Integration ◽

On Chip ◽

Scale Integration

The evolution of CMOS technology made possible integrated circuits with billions of transistors assembled into a single silicon chip, giving rise to the jargon Very-Large-Scale Integration (VLSI). VLSI circuits span a wide range class of applications, including Application Specific Circuits and Systems-On-Chip. The latter are responsible for fueling the consumer electronics market, especially in the segment of smartphones and tablets, which are responsible for pushing hardware performance requirements every new generation. The required clock frequency affects the performance of a VLSI circuit and induces timing constraints that must be properly handled by synthesis tools. This thesis focuses on techniques for timing closure of cellbased VLSI circuits, i.e. techniques able to iteratively reduce the number of timing violations until the synthesis of the synchronous digital system reaches the specified target frequency.

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Site-controlled telecom-wavelength single-photon emitters in atomically-thin MoTe2

Nature Communications ◽

10.1038/s41467-021-27033-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Huan Zhao ◽

Michael T. Pettes ◽

Yu Zheng ◽

Han Htoon

Keyword(s):

Single Photon ◽

Transition Metal Dichalcogenides ◽

Zeeman Splitting ◽

Liquid Nitrogen Temperature ◽

Single Photon Emitters ◽

Anisotropic Exchange Interaction ◽

Pillar Arrays ◽

Linearly Polarized ◽

Metal Dichalcogenides ◽

Photon Antibunching

AbstractQuantum emitters (QEs) in two-dimensional transition metal dichalcogenides (2D TMDCs) have advanced to the forefront of quantum communication and transduction research. To date, QEs capable of operating in O-C telecommunication bands have not been demonstrated in TMDCs. Here we report site-controlled creation of telecom QEs emitting over the 1080 to 1550 nm telecommunication wavelength range via coupling of 2D molybdenum ditelluride (MoTe2) to strain inducing nano-pillar arrays. Hanbury Brown and Twiss experiments conducted at 10 K reveal clear photon antibunching with 90% single-photon purity. The photon antibunching can be observed up to liquid nitrogen temperature (77 K). Polarization analysis further reveals that while some QEs display cross-linearly polarized doublets with ~1 meV splitting resulting from the strain induced anisotropic exchange interaction, valley degeneracy is preserved in other QEs. Valley Zeeman splitting as well as restoring of valley symmetry in cross-polarized doublets are observed under 8 T magnetic field.

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Single Photon Sources in Atomically Thin Materials

Annual Review of Physical Chemistry ◽

10.1146/annurev-physchem-042018-052628 ◽

2019 ◽

Vol 70 (1) ◽

pp. 123-142 ◽

Cited By ~ 39

Author(s):

Milos Toth ◽

Igor Aharonovich

Keyword(s):

Light Emission ◽

Single Photon ◽

Hexagonal Boron Nitride ◽

Transition Metal Dichalcogenides ◽

Proof Of Concept ◽

Scientific Discussion ◽

Two Dimensional Materials ◽

Metal Dichalcogenides ◽

On Chip ◽

Potential Use

Layered materials are very attractive for studies of light–matter interactions at the nanoscale. In particular, isolated quantum systems such as color centers and quantum dots embedded in these materials are gaining interest due to their potential use in a variety of quantum technologies and nanophotonics. Here, we review the field of nonclassical light emission from van der Waals crystals and atomically thin two-dimensional materials. We focus on transition metal dichalcogenides and hexagonal boron nitride and discuss the fabrication and properties of quantum emitters in these systems and proof-of-concept experiments that provide a foundation for their integration in on-chip nanophotonic circuits. These experiments include tuning of the emission wavelength, electrical excitation, and coupling of the emitters to waveguides, dielectric cavities, and plasmonic resonators. Finally, we discuss current challenges in the field and provide an outlook to further stimulate scientific discussion.

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Additive-Enhanced Exfoliation for High-Yield 2D Materials Production

Nanomaterials ◽

10.3390/nano11030601 ◽

2021 ◽

Vol 11 (3) ◽

pp. 601

Author(s):

Dinh-Tuan Nguyen ◽

Hsiang-An Ting ◽

Yen-Hsun Su ◽

Mario Hofmann ◽

Ya-Ping Hsieh

Keyword(s):

Large Scale ◽

2D Materials ◽

Transition Metal Dichalcogenides ◽

Spectroscopic Characterization ◽

High Yield ◽

Nanometer Scale ◽

Efficient Production ◽

Device Performance ◽

Metal Dichalcogenides ◽

Scale Deposition

The success of van-der-Waals electronics, which combine large-scale-deposition capabilities with high device performance, relies on the efficient production of suitable 2D materials. Shear exfoliation of 2D materials’ flakes from bulk sources can generate 2D materials with low amounts of defects, but the production yield has been limited below industry requirements. Here, we introduce additive-assisted exfoliation (AAE) as an approach to significantly increase the efficiency of shear exfoliation and produce an exfoliation yield of 30%. By introducing micrometer-sized particles that do not exfoliate, the gap between rotor and stator was dynamically reduced to increase the achievable shear rate. This enhancement was applied to WS2 and MoS2 production, which represent two of the most promising 2D transition-metal dichalcogenides. Spectroscopic characterization and cascade centrifugation reveal a consistent and significant increase in 2D material concentrations across all thickness ranges. Thus, the produced WS2 films exhibit high thickness uniformity in the nanometer-scale and can open up new routes for 2D materials production towards future applications.

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