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

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

Nature Communications ◽

10.1038/s41467-019-12421-0 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 32

Author(s):

Frédéric Peyskens ◽

Chitraleema Chakraborty ◽

Muhammad Muneeb ◽

Dries Van Thourhout ◽

Dirk Englund

Keyword(s):

Silicon Nitride ◽

Integrated Circuits ◽

Large Scale ◽

Single Photon ◽

Transition Metal Dichalcogenides ◽

Building Blocks ◽

Single Photon Emitters ◽

Metal Dichalcogenides ◽

On Chip ◽

Scale Integration

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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Characterization of the angular-dependent emission of nitrogen-vacancy centers in nanodiamond

Applied Physics B ◽

10.1007/s00340-020-07508-2 ◽

2020 ◽

Vol 126 (10) ◽

Author(s):

Justus Christinck ◽

Beatrice Rodiek ◽

Marco López ◽

Helmuth Hofer ◽

Hristina Georgieva ◽

...

Keyword(s):

Single Photon ◽

Collection Efficiency ◽

Nitrogen Vacancy ◽

Polarization Angle ◽

Single Photon Emitters ◽

Linearly Polarized ◽

Nitrogen Vacancy Centers ◽

Excitation Laser ◽

Nv Centers

Abstract We report on the characterization of the angular-dependent emission of single-photon emitters based on single nitrogen-vacancy (NV-) centers in nanodiamond at room temperature. A theoretical model for the calculation of the angular emission patterns of such an NV-center at a dielectric interface will be presented. For the first time, the orientation of the NV-centers in nanodiamond was determined from back focal plane images of NV-centers and by comparison of the theoretical and experimental angular emission pattern. Furthermore, the orientation of the NV-centers was also obtained from measurements of the fluorescence intensity in dependence on the polarization angle of the linearly polarized excitation laser. The results of these measurements are in good agreement. Moreover, the collection efficiency in this setup was calculated to be higher than 80% using the model of the angular emission of the NV-centers.

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Weakly damped acoustic plasmon mode in transition metal dichalcogenides with Zeeman splitting

Physical Review B ◽

10.1103/physrevb.89.235420 ◽

2014 ◽

Vol 89 (23) ◽

Cited By ~ 5

Author(s):

K. Kechedzhi ◽

D. S. L. Abergel

Keyword(s):

Transition Metal ◽

Transition Metal Dichalcogenides ◽

Zeeman Splitting ◽

Plasmon Mode ◽

Metal Dichalcogenides ◽

Acoustic Plasmon

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Enhancing and controlling valley magnetic response in MoS2/WS2 heterostructures by all-optical route

Nature Communications ◽

10.1038/s41467-019-12128-2 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 10

Author(s):

Jing Zhang ◽

Luojun Du ◽

Shun Feng ◽

Run-Wu Zhang ◽

Bingchen Cao ◽

...

Keyword(s):

Optical Transition ◽

Transition Metal Dichalcogenides ◽

Interlayer Coupling ◽

Zeeman Splitting ◽

Band Alignment ◽

Magnetic Response ◽

Coulomb Interactions ◽

All Optical ◽

Metal Dichalcogenides ◽

Ultrafast Charge Transfer

Abstract Van der Waals heterostructures of transition metal dichalcogenides with interlayer coupling offer an exotic platform to realize fascinating phenomena. Due to the type II band alignment of these heterostructures, electrons and holes are separated into different layers. The localized electrons induced doping in one layer, in principle, would lift the Fermi level to cross the spin-polarized upper conduction band and lead to strong manipulation of valley magnetic response. Here, we report the significantly enhanced valley Zeeman splitting and magnetic tuning of polarization for the direct optical transition of MoS2 in MoS2/WS2 heterostructures. Such strong enhancement of valley magnetic response in MoS2 stems from the change of the spin-valley degeneracy from 2 to 4 and strong many-body Coulomb interactions induced by ultrafast charge transfer. Moreover, the magnetic splitting can be tuned monotonically by laser power, providing an effective all-optical route towards engineering and manipulating of valleytronic devices and quantum-computation.

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