Narrow Line Width Quantum Emitters in an Electron-Beam-Shaped Polymer

Abstract

Solid-state single photon sources (SPSs) with narrow linewidth play an important role in many leading quantum technologies. Within the wide range of SPSs studied to date, single fluorescent molecules hosted in organic crystals stand out as bright, photostable SPSs with lifetime-limited optical resonance at cryogenic temperatures. Furthermore, recent results have demonstrated that photostability and narrow linewidths are still observed from single molecules hosted in a nanocrystalline environment, which paves the way for their integration with photonic circuitry. Polymers offer a compatible matrix for embedding nanocrystals and provide a versatile yet low-cost approach for making nanophotonic structures on chip that guide light and enhance coupling to nanoscale emitters. Here, we present a deterministic nanostructuring technique based on electron-beam lithography for shaping polymers with embedded single molecules. Our approach provides a direct mean of structuring the nanoscale environment of narrow linewidth emitters while preserving their emission properties.Ideal SPSs are isolated quantum systems displaying stable emission within a narrow linewidth 1 , which is fundamental for quantum technology applications such as entanglement and single photon

Narrow and Stable Single Photon Emission from Dibenzoterrylene inpara‐Terphenyl Nanocrystals

“…The size of the nanocrystals and DBT concentration are easy to control during synthesis. Similar nanocrystals have been shown to be suitable for integration into nanophotonic structures [1,26] . The comparable physical properties of pT and Ac suggest these techniques will also be suitable for pT.…”

“…The pT nanocrystals are robust to sublimation and can be filtered to select a desired nanocrystal size for particular applications. The small size of these nanocrystals makes them ideal for integration into nanophotonic structures, either directly [26] or after protection in a polymer shell, [25] enabling their use in future photonic quantum devices.…”

Polymer-encapsulated organic nanocrystals for single photon emission

“…Specifically, polycyclic aromatic hydrocarbons encased in organic crystals have been shown to generate photons of high purity that show potential for use in applications that exploit the single photon nature of their emission [2][3][4]. These molecules can be processed at ambient temperature [5] and can be readily incorporated into photonic structures [6][7][8]. Many of the desirable properties, including ease of manufacture, are due to weak van der Waals bonding in aromatic crystals, which while useful can lead to experimental difficulties.…”

Photon indistinguishability measurements under pulsed and continuous excitation

“…This is in line with the expected I value when considering I = Γ 1 /2Γ 2 × M = 0.54 ± 0.09, where the polarisation drift (0.95) and branching ratio (0.99) are contributing to M. The indistinguishability is limited primarily by excess thermal dephasing, which greater cooling can eliminate [18,29]. Additionally, these measurements highlight the potential of single molecules for quantum technology applications [15] when considering their integration into nanophotonic structures such as waveguides [32,33], patterned polymers [34,35] and cavities [36].…”