Lattice Surgery Demonstration Advances Fault-Tolerant Quantum Computing

A team of scientists, led by ETH Zurich researchers, recently demonstrated a way to entangle quantum bits via lattice surgery. The process enables engineers to make more powerful quantum computers, expanding the already impressive capabilities of these devices and opening the door for future adoption. Here’s what you need to know.

What Makes Quantum Computers Fundamentally Different

Quantum computers are seen by many as the next step in the evolution of computers. These devices can provide thousands of times more computational power, making them ideal for complex scientific calculations and more.

Quantum computers have proven to be much more powerful than traditional computers. They outperform traditional devices because they rely on qubits, superposition, entanglement, and interference to process information. This structure enables the processing of millions of computations in parallel.

Why Quantum Error Correction Is the Core Bottleneck

However, when it comes to storing quantum data, it’s much more difficult than traditional bits, which can be duplicated and stored. When retrieved, the duplicates can be cross-referenced to ensure the data is not corrupted.

Quantum error correction is much more complicated for several reasons. For one, quantum qubits can’t be copied in the same way as traditional bits. Instead, they rely on entangled states created between qubits. This fragile state can be destroyed easily.

Bit Flips and Phase Flips

Also, quantum computers need to deal with decoherence and phase shifts. Quantum computers are unique in that qubits can suddenly and without warning shift their phase from positive to negative. This issue has made storing quantum data over long periods more difficult.

How Engineers Fix this Issue

There are several ways in which engineers have sought to correct these quantum shifts. One popular method is to create a logical qubit from various other qubits. Once created, engineers will constantly apply error correction to ensure accuracy.

This process requires scientists to constantly measure the state of purpose-built stabilizers. These stabilizers enable engineers to monitor any changes in the qubit without altering its value. They accomplish this task by providing trackable bit and phase readouts.

This process creates data qubits. These qubits serve the purpose of storing the correction state. Problems arise because most quantum computers rely on two-dimensional arrays of superconducting qubits.

These qubits remain locked in space and can’t be moved without damaging the quantum state. Stabilizers help maintain stability. However, they can only work on qubits that are adjacent to each other, meaning they are ideal for two-dimensional qubit applications only and are very limited in their application.

Lattice Surgery on Quantum Bits Study

Seeking to improve quantum computing capabilities, scientists from ETH Zurich and the Paul Scherrer Institute published the “Lattice surgery realized on two distance-three repetition codes with superconducting qubits¹” study in Nature Physics.

The paper introduces a new methodology for quantum entanglement and stabilizers. Their new approach enables quantum computers to perform quantum operations between superconducting logical qubits while performing real-time error correction.

What Is Lattice Surgery in Quantum Computing?

At the core of this new development is lattice surgery. Lattice surgery splices topological codes across logical qubits. This approach supports 2D qubit arrangements alongside fault-tolerant gate operations.

Through the use of lattice surgery, the engineers were able to apply logic gates between encoded qubits even when not located next to each other. This strategy avoids direct qubit contact, reducing errors from decoherence.

Lattice surgery relies on the use of patches, which are qubits with stabilizers applied. The process stitches these gates together temporarily, enabling parity checks and a larger code space for processing. Notably, this work represents one of the first experimental demonstrations of lattice surgery performed between encoded logical qubits using superconducting surface-code hardware while maintaining real-time error correction during the operation.

How the Lattice Surgery Experiment Was Conducted

The engineers conducted several tests to ensure their calculations were correct. First, the team created a quantum device. The logic gate was composed of 17 superconducting qubits arranged in a rough square shape.

After entangling two, the engineers focus on the split operations. To do this, they encoded the logical qubits with bit-flip repetitions. They then monitored the stabilizers’ results every 1.66 microseconds while also performing bit flip and phase flip corrections.

The method splits the surface code square into halves, making it easier to track and test. Keenly, the test results demonstrated that their theories were correct.

Lattice Surgery on Quantum Bits – Test Results

The engineers noted that the bit flip errors were corrected in real time. They registered an improvement over non-encoded circuits put under the same process, with the result being that the engineers successfully created two logical qubits that were entangled with each other.

Lattice Surgery on Quantum Bits Benefits

There are many benefits that this study brings to the market. For one, it opens the door for more powerful and accurate quantum computers. The ability to reduce and encode fault tolerance and corrections into these devices will enable future iterations to provide more performance and stability.

Lattice Surgery on Quantum Bits: Real-World Applications & Timeline

There are several applications for this work. Primarily, this research will help to expand and improve the budding quantum computer sector. It provides a new level of stability to these devices, allowing engineers to create more powerful units that rely on even more qubits to drive operations.

Lattice Surgery on Quantum Bits Timeline

According to engineers, there’s still a lot of work to be done before this technology is ready and applied to today’s advanced quantum devices. However, you can expect to see this technology being applied to the sector in the next 7-10 years, alongside greater quantum computer adoption.

Lattice Surgery on Quantum Bits: Researchers

Researchers from several prominent institutions participated in this study. Specifically, D-PHYS Professor Andreas Wallraff led the research paper while Professor Markus Müller at RWTH Aachen University and Forschungszentrum Jülich co-authored the work.

The paper also lists Ilya Besedin, Michael Kerschbaum, Jonathan Knoll, Ian Hesner, Lukas Bödeker, Luis Colmenarez, Luca Hofele, Nathan Lacroix, Christoph Hellings, François Swiadek, Alexander Flasby, Mohsen Bahrami Panah, and Dante Colao Zanuz as contributors.

Lattice Surgery on Quantum Bits Future

The future of this technology is bright. The goal is to integrate it with other recent breakthroughs to help engineers achieve their overall goal of building useful quantum computers that rely on thousands of qubits rather than dozens.

Investing in Quantum Innovation

The quantum computing sector is dominated by several research firms that have invested millions into the tech. These groups continue to delve into this technology with an innovative spirit, helping to uncover previously thought impossible approaches. Here’s one company that has helped to foster future developments and adoption.

Rigetti Computing

Rigetti Computing was founded in 2013 by Chad Rigetti with the specific goal of building the world’s most powerful quantum computers using superconducting qubit technology. Unlike IonQ, which uses trapped ions, Rigetti’s focus on superconducting circuits aligns more closely with the ETH Zurich research involving lattice surgery on superconducting logical qubits.

In 2018, Rigetti demonstrated a 128-qubit chip, and the company has since pioneered the development of “Full-Stack” quantum computing. This includes the Fab-1 facility, the world’s first dedicated quantum foundry, where they design and manufacture their own quantum processors.

Rigetti has made significant strides in hybrid quantum-classical computing. Its Quantum Cloud Services (QCS) platform integrates quantum processors with high-performance classical infrastructure, a necessity for the real-time error correction discussed in current research. In 2021, Rigetti went public via a merger with Supernova Partners Acquisition Company II, listing on NASDAQ.

Today, Rigetti is actively developing its Ankaa-class systems, which utilize a square lattice of tunable couplers. This architecture is specifically designed to support the type of fault-tolerant operations and logical qubit encoding demonstrated in the latest ETH Zurich study.

Latest Rigetti Computing (RGTI) News and Performance

Lattice Surgery on Quantum Bits | Conclusion

Quantum computers promise unmatched computational power, but their fragility has made them too expensive for most people to ever use or own. This latest work will help to stabilize these devices, taking the world one step closer to an affordable and reliable option. For this reason and more, these engineers deserve a standing ovation.

Learn about other quantum computer breakthroughs here.

References

^{1. Besedin, I., Kerschbaum, M., Knoll, J., Hesner, I., Bödeker, L., Colmenarez, L., Hofele, L., Lacroix, N., Hellings, C., Swiadek, F., Flasby, A., Bahrami Panah, M., Colao Zanuz, D., Müller, M., & Wallraff, A. (2026). Lattice surgery realized on two distance-three repetition codes with superconducting qubits. Nature Physics, 1-6. https://doi.org/10.1038/s41567-025-03090-6}