The announcement matters because nearly every serious quantum computing and quantum sensing platform in operation today lives inside a cryogenic fortress. Superconducting processors must be chilled to temperatures below 3 kelvin, often just a few hundredths of a degree above absolute zero, and trapped-ion systems demand high-vacuum chambers and elaborate laser cooling apparatus. These requirements make quantum devices bulky, energy-hungry, and expensive, and they impose severe constraints on size, weight, and power—collectively known in the aerospace and defense worlds as SWaP. For quantum technology to escape the laboratory and enter widespread industrial use, engineers need devices that can survive and perform in the messy, warm environments of the real world.

The SUNY platform attacks that problem at the materials level. Rather than fighting to insulate fragile quantum states from thermal noise, the researchers engineered the quantum system itself to remain coherent under ambient conditions. Single erbium ions are embedded within silicon-based hollow nanopillars fabricated using advanced nanofabrication techniques. The choice of erbium is strategic: the ion’s optical transitions fall squarely in the telecom C-band, the wavelength range used by fiber-optic telecommunications networks worldwide. That means the quantum devices can, in principle, plug directly into the existing global optical infrastructure, a property that has long been a holy grail for quantum networking and distributed quantum sensing.

The performance figures reported for the platform are striking. The devices exhibit coherent operation in the telecom C-band with record-long optical quantum coherence times exceeding 500 microseconds at ambient conditions. According to the developers, that level of performance was previously attainable only in vacuum at temperatures more than 900 times lower than room temperature. In practical terms, the erbium ions hold onto their quantum information long enough—through superposition and entanglement, the twin resources that give quantum devices their advantage—for meaningful sensing and information processing operations to be carried out without the apparatus of a dilution refrigerator.

Readout, the process of extracting information from a qubit, presents its own challenge in most solid-state quantum systems, often requiring optical cavities and intricate filtering to achieve usable signal contrast. The SUNY platform sidesteps much of that complexity. The devices enable fast, high-contrast coherent optical readout in the visible range, at wavelengths around 518 nanometers, achieving contrast above 96 percent without the need for an optical cavity. Combined with narrow single-ion optical linewidths of less than 90 megahertz in the telecom band, the platform delivers the precision that quantum sensing and quantum communication applications demand, while keeping the device architecture comparatively simple.

Perhaps the most consequential claim is the platform’s compatibility with standard semiconductor foundry processes. Quantum technologies have historically been handcrafted affairs, assembled device by device in specialized cleanrooms, which has throttled their scalability. By contrast, the erbium-in-nanopillar architecture is described as fully compatible with the fabrication flows used by the mainstream semiconductor industry, opening a path to scalable, cost-effective mass production. The design also integrates seamlessly with photonic integrated circuits, the optical analog of electronic chips, positioning the technology as a plug-and-play component for compact quantum photonic systems rather than a bespoke laboratory curiosity.

The array architecture adds another layer of capability. Because each single-ion qubit in the nanopillar array is individually addressable, the platform functions as a scalable quantum sensor array rather than a single isolated device. The developers also describe the ions as qudits—quantum units that can encode information in more than two levels—pointing toward the room-temperature quantum processor concept in the project’s title. Individually addressable arrays of this kind are suited to distributed quantum sensing, in which many nodes work in concert to achieve measurement sensitivities beyond what any single sensor can reach, and to quantum networking schemes that link processors across optical fiber.

The application landscape for such a technology is broad. Quantum networking for secure communications and telecom-band quantum key distribution stand out, since erbium’s telecom-wavelength emission aligns naturally with the fiber infrastructure that carries the world’s data. Distributed quantum sensing arrays could benefit fields from navigation to biomedical imaging, where the developers suggest the devices could extend quantum sensing and imaging applications. Aerospace navigation and sensing systems are explicitly cited as a target domain, an area where the platform’s reduced size, weight, and power requirements give it a decisive edge over cryogenic alternatives that cannot realistically fly. Clock synchronization and distributed computation for a future Quantum Internet of Things round out the envisioned uses.

The Technology Accelerator Fund award is designed to bridge precisely the gap that often stalls academic breakthroughs: the distance between a validated laboratory result and a manufacturable, licensable product. The technology is currently available for licensing through the Research Foundation for the State University of New York, which lists it on SUNY TechConnect among discoveries available for commercial partnership. The Research Foundation, the nation’s largest research foundation supporting the country’s largest public university system, identifies quantum technologies and next-generation semiconductors among its strategic research priorities, and this platform sits squarely at the intersection of the two.

If the room-temperature performance holds up through scale-up and independent validation, the implications extend well beyond a single product category. A quantum device that operates in ambient conditions, rides on foundry-compatible silicon fabrication, speaks the telecom industry’s native wavelength language, and drops into photonic integrated circuits would remove nearly every practical barrier that has kept quantum sensing and quantum information science confined to specialized facilities. Challenges undoubtedly remain in engineering, yield, and integration, and the development stage details are available upon inquiry. But the demonstration that quantum coherence can survive at temperatures more than 900 times higher than current cryogenic systems require marks a genuine inflection point—one where materials science and engineering, rather than ever-deeper cooling, become the engine that carries quantum technology out of the cryostat and into the world.

Subject of Research: Room-temperature on-chip quantum sensing and processing using single-erbium ion qudits embedded in silicon-based hollow nanopillars

Article Title: Room temperature quantum processor based on on-chip arrays of single-ion qudits enabled by materials science and engineering

Article References: Room temperature quantum processor based on on-chip arrays of single-ion qudits enabled by materials science and engineering. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: quantum computing, erbium qubits, room temperature quantum, silicon nanopillars, quantum sensing, photonic integrated circuits, telecom C-band, quantum coherence, semiconductor foundry, SUNY Technology Accelerator Fund, quantum networking, qudits

The work, carried out by Abhishek Kumar Pandey, Deepak Jain, and Catherine Baskiotis, exploits spontaneous four-wave mixing, a nonlinear optical process in which two pump photons at the same frequency are annihilated to create a correlated pair of photons at two very different frequencies. Energy conservation forces the sum of the two new frequencies to equal twice the pump frequency, while momentum conservation, known as the phase-matching condition, dictates which frequency combinations can actually occur. In a waveguide, the phase-matching condition can be engineered by shaping the geometry of the silicon core, allowing the generated signal and idler photons to be tuned with remarkable precision across a wide spectral range.

What makes the new designs remarkable is the sheer distance between the two photons. The flagship design, targeted at atmospheric quantum key distribution, produces a signal photon at 3.905 micrometres, deep inside a mid-infrared atmospheric transparency window, while its idler partner lands at 1.541 micrometres in the telecom C-band. That separation of roughly 2,364 nanometres is dramatically larger than the record of about 1,125 nanometres theoretically reported in earlier all-solid silicon waveguide studies. Crucially, the design achieves this in the true quantum regime, where at most one photon pair is produced per pump pulse, rather than relying on the high pump powers used in classical demonstrations.

This distinction matters. Previous experiments with air-clad silicon waveguides demonstrated large signal-idler separations of about 2,058 nanometres, but only by using pump peak powers around 20 watts to achieve phase matching. In the quantum regime, pump power must be kept low to suppress multi-pair emission, and with those earlier designs the phase-matched separation collapsed to 1,780 nanometres, placing the mid-infrared photon outside any atmospheric transmission window. The new all-solid designs sidestep this problem by building the phase matching into the waveguide geometry itself, so that it holds even at the milliwatt pump levels required for single-pair emission.

The choice of an all-solid, fully oxide-clad structure is itself strategic. Air-clad waveguides suffer from significant scattering losses caused by sidewall roughness, because the optical mode interacts strongly with the etched surfaces. By surrounding the silicon core with fused silica cladding and a buried oxide layer, the proposed waveguides reduce the modal overlap with etched sidewalls, mitigating fabrication-induced scattering. The team’s calculations show that even at the longest signal wavelength, where silica is nominally opaque, the majority of the optical power remains confined to the silicon core, keeping total material attenuation over the 2-centimetre waveguide to acceptable levels.

To give their predictions quantitative teeth, the researchers adopted a model for the probability of photon-pair generation per pulse and validated it against published experimental data from photon-pair generation in photonic crystal fibre. By modelling the fibre as a simple step-index structure and feeding in the experimental parameters, they computed photon-pair rates that closely matched the measured values across a range of pump powers, outperforming the original theoretical treatment of those experiments. Because the model takes as inputs only the modal properties, the nonlinear index, and the operating conditions, the authors argue that the validation is generic and applies equally to the silicon waveguide geometries, whose modal fields they computed independently using full-vectorial finite element simulations.

Each of the three proposed waveguides is tailored to a specific application. Two designs generate signal photons at 3.265 and 3.461 micrometres, which coincide with absorption bands of methane and nitrogen dioxide respectively, the fingerprint region where these gases reveal their presence. Paired with telecom-band idlers, these sources could power schemes for sensing with undetected light, in which the mid-infrared photon probes the gas while only the telecom photon is ever detected, allowing the entire measurement to be performed with cheap, mature silicon-compatible detectors. The third design, optimised for atmospheric quantum key distribution, places the signal photon at 3.905 micrometres, where atmospheric transmission is dramatically better than at the 1.55-micrometre wavelength used in current daylight quantum communication experiments.

The shift to the mid-infrared could be transformative for free-space quantum communication. At 3 to 4 micrometres, the atmosphere exhibits reduced Rayleigh scattering, lower solar background noise, and greater resistance to weather-related variations, all of which translate into more reliable quantum links and an improved ability to operate in daylight. Shrinking the photon-pair source onto a chip also addresses a critical constraint for satellite payloads, where every gram of mass and cubic centimetre of volume counts. Silicon-on-insulator fabrication is cheap, scalable, and compatible with existing CMOS foundries, making the prospect of flight-qualified quantum sources considerably more realistic than with bulk nonlinear crystals.

The team also addressed the practical obstacles that have plagued mid-infrared quantum optics in silicon. Spontaneous Raman scattering, which can contaminate photon-pair spectra, is predicted to be negligible because the generated photons lie more than 330 Raman linewidths away from the silicon Raman gain peak, placing the Raman gain at the signal frequencies at the level of one part in a million. Two-photon absorption, the bane of silicon nonlinear optics at telecom wavelengths, falls off sharply for pump wavelengths above 1.9 micrometres, and the chosen pump wavelengths between 2.1 and 2.21 micrometres sit in a sweet spot combining strong Kerr nonlinearity with suppressed carrier generation. Numerical tolerance studies further showed that small fabrication imperfections of plus or minus 10 nanometres in the core dimensions cause only slight wavelength drifts that can be compensated by tuning the pump laser.

The predicted operating points are within reach of existing technology. Each design targets a probability of photon-pair generation per pulse of about 0.05, a value considered a practical compromise between source brightness and multi-pair suppression, and achieves this with peak pump powers between 9.2 and 32.2 milliwatts from 5-picosecond pulses. Such pump powers are already delivered by mature thulium and holmium-doped solid-state lasers around 2 micrometres, while integrated 2-micrometre laser sources continue to advance toward the required output levels. With mid-infrared single-photon detectors, including superconducting nanowire devices and frequency-upconversion schemes, progressing rapidly, the authors argue that their chip-scale sources could soon move from simulation to experiment, opening a path toward quantum communication and sensing that spans from the fingerprint region of the molecules to the heart of the telecom infrastructure.

Subject of Research: Silicon waveguide design for quantum-correlated photon-pair generation bridging mid-infrared and telecom bands via spontaneous four-wave mixing

Article Title: Quantitative study of silicon waveguides for the generation of quantum correlated photon pairs bridging mid-infrared and telecom bands

Article References: Pandey, A. K., Jain, D., & Baskiotis, C. (2026). Quantitative study of silicon waveguides for the generation of quantum correlated photon pairs bridging mid-infrared and telecom bands. Results in Optics, 25, Article 101158. https://doi.org/10.1016/j.rio.2026.101158

Image Credits: AI Generated

DOI: 10.1016/j.rio.2026.101158

Keywords: silicon photonics, quantum optics, photon pairs, four-wave mixing, mid-infrared, telecom C-band, quantum key distribution, gas sensing, silicon-on-insulator, phase matching, Raman scattering, integrated photonics