Tunable Nanoengineered Transition Metal Dichalcogenides for Quantum Nanophotonics

Projektinformationen

TuneTMD

ID Finanzhilfevereinbarung: 101076437

DOI

10.3030/101076437

EK-Unterschriftsdatum 29 November 2022

Startdatum 1 Januar 2023

Enddatum 31 Dezember 2027

Finanziert unter

• European Research Council (ERC)

Gesamtkosten

€ 1 499 578,00

EU-Beitrag

€ 1 499 578,00

Koordiniert durch

DANMARKS TEKNISKE UNIVERSITET
Denmark

Periodic Reporting for period 1 - TuneTMD (Tunable Nanoengineered Transition Metal Dichalcogenides for Quantum Nanophotonics)

Berichtszeitraum: 2023-01-01 bis 2025-06-30

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

The world is entering a new era of quantum technology, where the ability to manipulate individual photons could revolutionize computing, communication, and cryptography. At the heart of this transformation lies the need for reliable single-photon sources (SPSs) that can generate efficient, indistinguishable photons on demand. These photons serve as quantum bits (qubits) - the building blocks of quantum information.
A major challenge in realizing practical quantum photonic technologies is the lack of scalable and tunable SPSs. Conventional platforms offer limited control over photon emission and are difficult to integrate into scalable photonic systems. Moreover, to enable real-world quantum applications, it is essential to build fully integrated quantum photonic circuits, where SPSs, waveguides, beamsplitters, and detectors are integrated on a single chip.

The TuneTMD project is working toward a groundbreaking solution: a fully tunable, chip-scale quantum photonic circuit based on transition metal dichalcogenides (TMDs) - a class of two-dimensional materials with exceptional optical and electronic properties. These atomically thin materials can be stacked and engineered at the nanoscale, allowing unprecedented control over their quantum emission characteristics. Our research focuses on three key objectives:

1. Developing tunable, low-noise SPSs through strain and defect engineering combined with electrical biasing, enabling active control over single-photon properties.
2. Designing on-chip quantum photonic components, including TMD-based waveguides, beamsplitters, and detectors, to route and manipulate photons within integrated circuits.
3. Demonstrating integrated quantum circuits by combining these elements to perform on-chip quantum interference experiments, validating the feasibility of monolithic photonic platforms.

By advancing each of these areas, TuneTMD is laying the foundation for scalable, integrated quantum photonic technologies - bridging the gap between fundamental research and practical quantum applications.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

Over the past 30 months, our research team has made significant strides in achieving this vision, tackling key challenges in single-photon generation, integrated photonic components, and single-photon detection.

1. Tunable, low-noise single-photon sources: A key objective of the project was to develop tunable, low-noise single-photon sources (SPSs) using TMDs. Generating indistinguishable single photons has long been a challenge due to charge noise, phonon interactions, and material imperfections.
Through advanced strain- and defect engineering, we established a deterministic fabrication technique for developing highly-polarised quantum emitters with high single-photon purity (npj 2D Materials and Applications, 2024).
In parallel, our theoretical studies uncovered new insights into phonon-induced decoherence in TMD quantum emitters. By carefully analyzing the interplay between excitation schemes and phonon interactions, we demonstrated how specific optical excitation methods could enhance single-photon properties (Physical Review B, 2024). This theoretical foundation directly guided our experimental approach, leading to the development of phonon-assisted excitation schemes that significantly improved single-photon stability and emission coherence.
Taking this progress further, we developed an electrical biasing method to mitigate charge noise, a major bottleneck in achieving indistinguishability. By combining the encapsulation technique with electrical biasing, we successfully demonstrated highly stable, resolution-limited single-photon emission with active tunability.

2. Novel on-chip photonic components: To enable fully integrated quantum circuits, we developed key photonic components—waveguides, beamsplitters, and grating couplers—based on multilayer TMDs. A key challenge was optimizing nanostructuring to preserve the materials’ optical quality. Through careful fabrication and characterization, we demonstrated low-loss, integrated TMD photonic devices. These results were presented at major conferences, with a full publication planned for Fall 2025. This progress brings us closer to seamless integration of quantum emitters with on-chip photonic circuitry.

3. TMD single-photon detectors: To complete the quantum photonic circuit, we pioneered the development of superconducting nanowire single-photon detectors (SNSPDs) using layered TMDs with intrinsic superconductivity. In our recent work (arXiv:2503.22670) we demonstrated the first functional SNSPDs based on nanostructured NbSe2, achieving stable superconducting performance despite sub-200 nm wire widths and extensive nanofabrication. These detectors were encapsulated with hBN to ensure long-term stability and oxidation protection. Initial photodetection measurements confirmed clear single-photon sensitivity and robust switching behavior. This work marks a major step toward monolithic integration of photon generation and detection within the same 2D material platform. Ongoing efforts focus on optimizing detector efficiency and integrating these SNSPDs with on-chip TMD quantum emitters.

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

During the first project period, the TuneTMD project achieved major milestones in quantum light generation, noise suppression, and superconducting photodetection using transition metal dichalcogenides (TMDs). These results push the frontiers of quantum nanophotonics and establish a foundation for integrated, scalable quantum technologies based on nanoengineered 2D materials.

A central challenge in quantum photonics is generating stable, high-purity single photons with controlled polarization, wavelength, and minimal noise. TuneTMD addressed this through several innovations:
• Polarization-Controlled TMD Emitters: Using deterministic strain engineering, we achieved robust control over the polarization of single-photon emission, a key step toward indistinguishable photons for quantum circuits.
• Low-Noise, Electrically Tunable Emitters: We developed an approach combining hBN encapsulation and electrical biasing to suppress charge noise, dramatically improving photon indistinguishability and enabling active tunability.
• Phonon-Assisted Excitation: By introducing phonon-assisted excitation in bilayer TMD quantum emitters, we enhanced the coherence and stability of single-photon emission, mitigating decoherence from exciton-phonon interactions.

In parallel, we demonstrated the first superconducting nanowire single-photon detectors (SNSPDs) based on 2D TMDs with intrinsic superconductivity. Optimized nanofabrication and hBN encapsulation preserved superconducting behavior in sub-200 nm NbSe2 nanowires. Preliminary photodetection results confirmed efficient single-photon sensitivity at cryogenic temperatures.

Together, these results pave the way for all-TMD quantum photonic platforms where sources and detectors are monolithically integrated. In the next phase, we will focus on integrating these components into on-chip waveguides—an essential step toward scalable quantum photonic circuits and future quantum technologies.