Periodic Reporting for period 1 - QUANTITATIVE (A MILLION QUBIT QUANTUM COMPUTER - HIGHLY SCALABLE SOLID STATE QUANTUM COMPUTINGPLATFORM WITH NATIVE OPTICAL NETWORKING)
Periodo di rendicontazione: 2024-12-01 al 2025-11-30
In this project we build the 3 layers of the solution – the multi-qubit layer, the photonic interconnect layer and the control layer, and integrate them together to form a synchronized and highly scalable quantum computing device.
1) Quantum layer – A) An improved design of the qubit elements B) updated PDK for the diamond Fab C) The qubit layer was produced in several cycles in the company’s diamond fab facility and achieved it first year’s target for scalability and manufacturability.
2) Photonic layer – A) improved designs of the photonic layer – including improved alignment with the quantum layer, improved waveguides and improved funcitonalaity of the passive and active building block of the photonic Integrated Circuit (PIC). B) A PDK was developed in the company for manufacturing in a commercial tier 1 Fab. C) The photonic layer was produced in a commercial silicon photonic Fab and has passed the first phase out of three.
3) Control layer – first integration with a 3rd party control platform was achieved
“Highly resilient, error-protected quantum gates in a solid-state quantum network node” the company presents for single qubit and two-qubits implemented on solid-state nitrogen-vacancy (NV) center in diamond an improvement of error per gate by a factor of 9, corresponding to a fidelity of 99.9988%.
These results establish a new state-of-the-art benchmark and demonstrate that NV centers can support gate fidelities competitive with leading superconducting and trapped-ion platforms while offering unique advantages for quantum networking, including optical connectivity and long-lived nuclear memories.
Here is the overview of the results:
High-fidelity quantum gates are a cornerstone of any quantum computing and communications architecture. Realizing such control in the presence of realistic errors at the level required for beyond-threshold quantum error correction is a long-standing challenge for all quantum hardware platforms. Here we theoretically develop and experimentally demonstrate error-protected quantum gates in a solid-state quantum network node. Our work combines room-temperature randomized benchmarking with a new class of composite pulses that are simultaneously robust to frequency and amplitude, affecting random and systematic errors. We introduce Power-Unaffected, Doubly-Detuning-Insensitive Gates (PUDDINGs) - a theoretical framework for constructing conditional gates with immunity to both amplitude and frequency errors. For single-qubit and two-qubit CNOT gate demonstrations in a solid-state nitrogen-vacancy (NV) center in diamond, we systematically measure an improvement in the error per gate up to a factor of 9. By projecting the application of PUDDING to cryogenic temperatures we show a record two-qubit error per gate of 1.2X10-5 , corresponding to a fidelity of 99.9988% , far below the thresholds required by surface and color code error correction. These results present viable building blocks for a new class of fault-tolerant quantum networks and represent the first experimental realization of error-protected conditional gates in solid-state systems.
The full article can be downloaded from the following address:
https://arxiv.org/abs/2512.05322(si apre in una nuova finestra)
The effects of the results on the industry:
More broadly, the convergence of precise pulse engineering, detailed noise modeling, and quantitative benchmarking realized in our work marks a significant step toward practical, distributed quantum computing. We expect the ideas introduced in this work to inform the design of robust conditional gates across a wide variety of quantum technologies and to play a central role in the development of scalable, fault-tolerant quantum network architectures.