By Andrea Husseini and Aniket Datta
Today's best quantum computers can only achieve a few hundred error-free quantum operations. We need millions to outperform supercomputers. Correcting quantum errors involves massively complex data processing tasks. Riverlane is building a quantum error correction stack that identifies errors and sends the corrective actions back to a qubit control system for execution on the quantum processor.
An important challenge is making sure that the QEC stack and qubit control system can exchange information fast enough during a real-time experiment so the quantum computer can run calculations at useful speeds.
The QEC interface (QECi) developed by Riverlane, defines communication between a control system and a QEC stack to execute real-time quantum error correction experiments.
The adoption of the QECi has multiple benefits for the quantum computing industry. It:
- Reduces integration issues when adding the QEC stack.
- Minimises duplication of effort, allowing independent upgrades of the control system and QEC stack.
- Provides long-term interoperability of the QEC stack with your favoured solution.
- Enables quantum computer developers to concentrate on scaling their qubits and making the MegaQuop machine. This will be a practical quantum computer able to perform over a million logical operations without error.
Riverlane wants to help the quantum computing community through its leadership in QEC and believes the quickest way to practical fault tolerant computing is by reducing the number of bottlenecks that will limit progress. By using QECi, any quantum computer can operate with any QEC stack. This allows the hardware developers to use any QEC solution and not be tied to a specific vendor. This helps the hardware developers by reducing integration issues, thus allowing hardware developers to concentrate on scaling their qubit technologies.
Example of implementing QECi
Here we describe an example of connecting a control system and a QEC stack using QECi. The three layers in the control system and QEC stack that need to be considered are the physical layer, the data layer and the protocol layer.
The physical layer ensures that there is a reliable link between the control system and QEC stack. This takes care of all necessary classical error correction on the data transfer and allows any two FPGAs (from different manufacturers or product families) to communicate with each other in real-time. This allows for a smoother integration and easier adoption, where partners focus mainly on implementing the data layer and the protocol layer.
The data layer specifies the format in which data is exchanged between the control system and QEC stack. It defines a payload (for example, qubit readout data) and a header, which contains information about the type of payload, where it is coming from and where it is going to.
The protocol layer comes into play when we start performing logic. It allows the control system and the QEC stack to keep track of where in the logical circuit they are and which operation they are currently performing. This layer also enables the control system and QEC stack to seamlessly perform branching logic, such as logical T gates.
Qblox, a leading qubit control system company, is working with Riverlane to adopt QECi. Together, we are using the QECi to communicate between Riverlane’s QEC stack and Qblox’s control system.
Some of this work came about as part of a £2.1m European Innovation Council (EIC) Transition grant funded by the Horizon Europe guarantee and backed by the Department for Science, Innovation & Technology (DSIT). The goal of the work is to build a QEC stack that supports real-time decoding of quantum memories and operations and demonstrates the stack can be integrated into a commercial control system.
In this project we are taking strides towards a real-time connection between Deltaflow 2, the QEC stack, and Qblox’s control system, where Qblox massively scaling low latency data network tightly integrates with QECi. This involves data routing and processing so that qubit readout data and decoder results can be transferred between the control system and the QEC stack in real time.
“Qblox is on a mission to provide control systems for fault-tolerant quantum computers. Supporting QECi in our control system allows us to offer integrated solutions for real-time fault tolerance with any compatible QEC stack while focusing on our unique expertise in low-latency data orchestration and qubit control. The scalability of QECi ensures long-term interoperability as the number of controlled qubits increases towards millions. With Riverlane we have found the partner to connect our massively-scalable low-latency control system to world-class decoders that will realize the world’s most advanced fault-tolerant quantum computers.”
Says Niels Bultink – CEO of Qblox.
Our other partners, including Rigetti Computing and Infleqtion, are already adopting QECi to enhance their capabilities.
Find out more about QECi