We demonstrate large-range tuning of the optical transition of Tin-Vacancies (SnV) in diamond using electro-mechanical-induced strain, realizing >40 GHz tuning. We employ real-time feedback on the strain environment to stabilize the resonant frequency.

The development of color centers in silicon enables scalable quantum technologies by combining telecom-wavelength emission and compatibility with mature silicon fabrication. However, large-scale integration requires precise control of each emitter's optical transition to generate indistinguishable photons for quantum networking. Here, we demonstrate a foundry-fabricated photonic integrated circuit (PIC) combining suspended silicon waveguides with a microelectromechanical (MEMS) cantilever to apply local strain and spectrally tune individual G-centers. Applying up to 35 V between the cantilever and the substrate induces a reversible wavelength shift of the zero-phonon line exceeding 100 pm, with no loss in brightness. Moreover, by modeling the strain-induced shifts with a digital twin physical model, we achieve vertical localization of color centers with sub-3 nm vertical resolution, directly correlating their spatial position, dipole orientation, and spectral behavior. This method enables on-demand, low-power control of emission spectrum and nanoscale localization of color centers, advancing quantum networks on a foundry-compatible platform.

Detecting nonclassical light is a central requirement for photonics-based quantum technologies. Unrivaled high efficiencies and low dark counts have positioned superconducting nanowire single-photon detectors (SNSPDs) as the leading detector technology for integrated photonic applications. However, a central challenge lies in their integration within photonic integrated circuits, regardless of material platform or surface topography. Here, we introduce a method based on transfer printing that overcomes these constraints and allows for the integration of SNSPDs onto arbitrary photonic substrates. With a kinetically controlled elastomer stamp, we transfer suspended SNSPDs onto commercially manufactured silicon and lithium niobate on insulator integrated photonic circuits. Focused ion beam metal deposition then wires the detectors to the circuits, thereby allowing us to monitor photon counts with >7% detection efficiencies. Our method eliminates detector integration bottlenecks and provides new venues for versatile, accessible, and scalable quantum information processors.

The negatively charged tin-vacancy (SnV⁻) center in diamond has emerged as a promising platform for quantum computing and quantum networks. To connect SnV⁻ qubits in large networks, in situ tuning and stabilization of their optical transitions are essential to overcome static and dynamic frequency offsets induced by the local environment. Here, we report on the large-range optical frequency tuning of diamond SnV⁻ centers using micro-electro-mechanically mediated strain control in photonic integrated waveguide devices. We realize a tuning range of >40 GHz, covering a major part of the inhomogeneous distribution. In addition, we employ real-time feedback on the strain environment to stabilize the resonance frequency and mitigate spectral wandering. These results provide a path for on-chip scaling of diamond SnV-based quantum networks.

Artificial atoms in solids are leading candidates for quantum networks, scalable quantum computing, and sensing, as they combine long-lived spins with mobile photonic qubits. Recently, silicon has emerged as a promising host material where artificial atoms with long spin coherence times and emission into the telecommunications band can be controllably fabricated. This field leverages the maturity of silicon photonics to embed artificial atoms into the world’s most advanced microelectronics and photonics platform. However, a current bottleneck is the naturally weak emission rate of these atoms, which can be addressed by coupling to an optical cavity. Here, we demonstrate cavity-enhanced single artificial atoms in silicon (G-centers) at telecommunication wavelengths. Our results show enhancement of their zero phonon line intensities along with highly pure single-photon emission, while their lifetime remains statistically unchanged. We suggest the possibility of two different existing types of G-centers, shedding new light on the properties of silicon emitters.

We demonstrate a hybrid device consisting of a thin film lithium niobate membrane transfer-printed onto a silicon nitride ring resonator. We measure quality factors in the 10⁵ range at telecom wavelengths.

Colour centres in diamond have emerged as a leading solid-state platform for advancing quantum technologies, satisfying the DiVincenzo criteria¹ and recently achieving quantum advantage in secret key distribution². Blueprint studies^3–5 indicate that general-purpose quantum computing using local quantum communication networks will require millions of physical qubits to encode thousands of logical qubits, presenting an open scalability challenge. Here we introduce a modular quantum system-on-chip (QSoC) architecture that integrates thousands of individually addressable tin-vacancy spin qubits in two-dimensional arrays of quantum microchiplets into an application-specific integrated circuit designed for cryogenic control. We demonstrate crucial fabrication steps and architectural subcomponents, including QSoC transfer by means of a ‘lock-and-release’ method for large-scale heterogeneous integration, high-throughput spin-qubit calibration and spectral tuning, and efficient spin state preparation and measurement. This QSoC architecture supports full connectivity for quantum memory arrays by spectral tuning across spin–photon frequency channels. Design studies building on these measurements indicate further scaling potential by means of increased qubit density, larger QSoC active regions and optical networking across QSoC modules.

We show enhanced single-photon emission from artificial atoms in silicon by coupling them to cavities with high quality factors and small mode volumes, thus enabling enhanced light-matter interactions which are crucial for quantum technologies.

A central goal for quantum technologies is to develop platforms for precise and scalable control of individually addressable artificial atoms with efficient optical interfaces. Color centers in silicon, such as the recently-isolated carbon-related G-center, exhibit emission directly into the telecommunications O-band and can leverage the maturity of silicon-on-insulator photonics. We demonstrate the generation, individual addressing, and spectral trimming of G-center artificial atoms in a silicon-on-insulator photonic integrated circuit platform. Focusing on the neutral charge state emission at 1278 nm, we observe waveguide-coupled single photon emission with narrow inhomogeneous distribution with standard deviation of 1.1 nm, excited state lifetime of 8.3 ± 0.7 ns, and no degradation after over a month of operation. In addition, we introduce a technique for optical trimming of spectral transitions up to 300 pm (55 GHz) and local deactivation of single artificial atoms. This non-volatile spectral programming enables alignment of quantum emitters into 25 GHz telecommunication grid channels. Our demonstration opens the path to quantum information processing based on implantable artificial atoms in very large scale integrated photonics.

We demonstrate silicon color centers coupled to foundry-compatible silicon waveguides. We produced G-centers via carbon implantation in commercial silicon-on-insulator waveguides and measure through-waveguide single-photon emission in the telecommunications O-band.

Optical quantum technologies require strong light-matter interaction. We couple silicon color center ensembles to high-Q/V cavities and show enhanced emission in the telecommunications O-band.