Caltech’s ‘Ocelot’ Becomes Latest Error Squashing Advancement in Quantum Computing

Last year, McKinsey & Company published a comprehensive report etching out the future trajectory of quantum computing. The report was ambitiously named ‘The Rise of Quantum Computing.’ However, the ambitions were not unfounded.

McKinsey said that the journey towards Quantum Computing was driven by the accelerated pace of technological breakthroughs, increased flow of investments, and a proliferation of the start-up ecosystem.

All these factors were responsible for driving business leaders to plan for robust quantum computing strategies. Updated McKinsey analysis for the third annual Quantum Technology Monitor reveals that four sectors—chemicals, life sciences, finance, and mobility—will likely see the earliest impact from quantum computing and could gain up to $2 trillion by 2035.

For Quantum Computing to grow as McKinsey envisions, it would require a thriving innovation ecosystem. In one of the most cutting-edge breakthroughs in this regard, scientists at the AWS Center for Quantum Computing on Caltech’s campus¹ have figured out a way to suppress errors in quantum computers—a problem that could become the greatest hurdle in building future-ready quantum machines. 

What Was the ‘Problem’?

Building a general-purpose quantum computer that goes beyond studying niche areas of physics remains a challenge due to its inherent sensitivity to noise. Researchers have found that vibrations, heat, electromagnetic interference from cell phones and Wi-Fi networks, and even cosmic rays and radiation from outer space can all knock qubits—quantum bits—knocking them out of their quantum state and cause significantly more errors than classical computers.

To elaborate with more scientific precision, the research, titled Hardware-Efficient Quantum Error Correction Via Concatenated Bosonic Qubits, works towards building quantum computers that would incorporate quantum error correction. It would have a logical qubit redundantly encoded in many noisy physical qubits.

Ocelot: The Solution

In simpler words, the team of scientists from AWS and Caltech demonstrated a new quantum chip architecture for suppressing errors using a type of qubit known as a cat qubit.

Cat Qubits are not new, though; they were first proposed in 2001. Since then, researchers have continuously developed and refined them. The breakthrough for the team came with the creation of the first scalable cat qubit chip, designed to efficiently reduce quantum errors. The chip was named Ocelot after the spotted wild cat while also referencing the internal “oscillator” technology that underlies the cat qubits.

According to researchers, error rates have to be a billion times better than they are today. Only then could quantum computers be termed successful. The new invention would help us reach the target faster:

According to Oskar Painter (PhD’ 01), John G Braun is a professor of applied physics and physics at Caltech and the head of quantum hardware at AWS:

“Error rates have been going down about a factor of two every two years. At this rate, it would take us 70 years to get to where we need to be. Instead, we are developing a new chip architecture that may be able to get us there faster. That said, this is an early building block. We still have a lot of work to do.”

The researchers, while highlighting the drawbacks of the current qubit technologies, say that they may require thousands of additional qubits to provide the desired level of protection from errors, which is similar to newspaper outlets employing a huge building of fact-checkers to verify the accuracy of its articles instead of just a small team. This makes the process crumble due to the cost of overheads, which is excessive and unwieldy.

Fernando Brandão, Bren Professor of Theoretical Physics at Caltech and director of applied science at AWS, admits this problem. He says:

“So, we are trying new approaches to error correction that will reduce the overhead.”

The Oscillation Tech at the Foundation of Ocelot

The team employs a type of qubit formed from superconducting circuits made of microwave oscillators, where 1 and 0 states—representing the qubit—are defined as two distinct large-scale oscillation amplitudes. This approach is aimed at making the qubit states stable and impervious to bit-flip errors.

Once the bit-flip errors are taken care of, the other error that remains to be corrected is the phase-flip error. To detect phase errors, the Ocelot chip deploys four ancillary qubits.

The team’s simple repetition code is effective at catching the phase flip errors and improves as the code increases from three cat qubits to five cat qubits.

The Path Forward for the Research

Currently, the demonstration is at a proof-of-concept stage. But, researchers involved in the process, like Painter, are excited by the performance Ocelot has demonstrated. He says:

“It’s a very hard problem to tackle, and we will need to continue to invest in basic research while staying connected to, and learning from, important work being done in academia.”

As Painter hinted, these improvements need corporate patrons. It requires investments to scale up. In the following segments, we discuss a couple of such companies that are doing significant work in the field of Quantum Computing.

1. IBM (IBM -0.91%)

IBM, the globally revered tech giant, remains committed to making quantum computing practical to the world. It operates a dedicated division, IBM Quantum, which offers access to the largest quantum computing fleet in the world via Qiskit—a platform providing software tools and services to create a holistic programming model for utility.

IBM’s QuantumSafe, for instance, secures an enterprise for the quantum future, offering its 127-qubit systems for free. Additionally, the platform provides access to systems, documentation, and learning resources all in one place.

The company is committed to making quantum computing responsible. The mission statement of the company in this regard is to be “the catalyst to make the world work better,” and it runs a Responsible Quantum Initiative to ensure that our development is in line with that mission.

According to IBM, Responsible Quantum Computing is quantum computing that’s aware of its effects. The company has crafted five Responsible Quantum Principles for developing and deploying quantum technology that the team follows internally. These principles are as follows:

• Make a positive societal impact.
• Explore use cases with foresight.
• Promote IBM’s products accurately
• Make consistent, principled decisions
• Build a diverse and inclusive quantum community

With steady progress along the IBM Quantum™ Roadmap, the company is upgrading its quantum platform to deliver enterprise-grade cloud services.

More specifically, the company is upgrading with enterprise-grade infrastructure. However, to remain seamless for its legacy users, the company will ensure that the final version of the new IBM Quantum Platform will be very similar to the version we use now.

The company will ensure that users continue to have access to the documentation and learning resources it has traditionally housed. However, the upgrade will enhance the value with boosted performance and powerful features.

Among specific features, the upgrade will come with enhanced data privacy and security, a streamlined notifications experience, better platform navigation, multiple language options for users who speak languages other than English, etc.

For enhanced levels of public accessibility, IBM has built a Quantum Network. The network supports businesses, universities, laboratories, and industry leaders on their journeys to advancing quantum utility. Members gain access to learning resources, experts, and events to accelerate research and foster collaboration.

For the latest financial year, IBM registered a revenue of $62.8 billion, up 1 percent, up 3 percent at constant currency.

While speaking about its results, Arvind Krishna, IBM chairman, president, and chief executive officer, said:

“Three years ago, we laid out a vision for a faster-growing, more profitable IBM. I’m proud of the work the IBM team has done to meet or exceed our commitments. With our focused strategy, enhanced portfolio, and culture of innovation, we’re well-positioned for 2025 and beyond and expect revenue growth of at least five percent and free cash flow of about $13.5 billion this year.”

2. Microsoft (MSFT +3.13%)

Another leading tech giant to do pioneering work in the field of quantum computing is Microsoft. Its vision is to accelerate scientific discovery through industry-leading advanced technology that would accelerate scientific discovery.

Microsoft has the following four quantum solutions:

• Microsoft Quantum Compute Platform: A platform that enables a new generation of quantum applications.
• Azure Quantum Elements: It is a purpose-built solution to accelerate scientific discovery.
• Quantum Hardware: Solution targeted at unlocking a scaled quantum supercomputer.
• Quantum Networking: A solution that enables distributed quantum computing with a quantum network

If we look at these solutions from the prism of their users, different solutions provide different services. For instance, through the Microsoft Quantum Compute platform, it is possible to gain access to state-of-the-art quantum hardware, reliable logical qubits, advanced AI models, and HPC simulations to accelerate scientific discoveries.

The Azure Quantum Elements solution helps accelerate scientific discovery for chemistry and materials science through High-Performance Computing, Artificial Intelligence, and a future quantum computer.

Through Microsoft Quantum Hardware, the company is engineering a quantum supercomputer that will enable the world to tackle problems like reversing climate change and improving food security.

Finally, through Microsoft Quantum Networking, the company aims to deliver quantum networking capabilities to scale quantum clusters and enable new security-related applications.

If we delve deeper into Microsoft Quantum Hardware, we will realize that it’s indeed a breakthrough. It is a breakthrough because it pioneers measurement-only quantum computing—a fundamentally simpler way to control quantum information.

Powered by a Topological Core, Microsoft’s processor is designed to scale to a million qubits—enough computing power to tackle humanity’s toughest challenges in energy, medicine, and beyond.

In this regard, one could look at Microsoft’s paper, published in Nature, titled ‘Interferometric Single-Shot Parity Measurement In Inas–Al Hybrid Devices.’

Overall, Microsoft Quantum Hardware stands on the following foundational pillars:

• Scalability: The solution is designed to enable useful quantum computing
• Stability: It is resistant to errors at the hardware level.
• Small: The hardware is capable of fitting more than one million qubits in one single chip.
• Fast: It takes less than 1 microsecond per operation.
• Controllable: Its voltage pulses provide precise digital control.

If we look at the key features of Azure Quantum Elements, its generative chemistry leverages the power of generative AI to greatly simplify the discovery and design of novel molecules with desired properties. The accelerated DFT feature determines the properties of molecules with thousands of atoms in hours, providing a substantial increase in speed over other DFT codes.

Moreover, the open ecosystem helps make use of familiar software solutions optimized for Azure Quantum Elements.

Microsoft’s Azure Quantum Elements has helped several research institutions and companies deliver solutions for the future. For instance, Unilever has harnessed the power of Microsoft supercomputing and AI services to support its R&D transformation and product innovation.

Microsoft and Pacific Northwest National Laboratory joined forces to identify a new material that holds the potential for better batteries. The company has collaborated with AspenTech to design a quantum chemistry workflow. It has joined forces with Johnson Matthey to speed up hydrogen fuel cell innovation with Azure Quantum.

Microsoft and 1910 Genetics partnered to turbocharge R&D productivity for the pharmaceutical industry, while it partnered with InQuanto to accelerate quantum computational chemistry. Altogether, Microsoft has played a key role in demonstrating how Quantum Computing could become efficiently useful for a robust and efficient future.

In 2024, the year that marked Microsoft’s 50th year as a company. The company delivered over $245 billion in annual revenue, up 16 percent year-over-year, and over $109 billion in operating income, up 24 percent. The company categorically said it was focused on incubating technical products and support solutions with transformative potential for the future of cloud computing and continued company growth, such as quantum computing and advanced AI for science.

While large tech companies are doing the best they can, institutional research is not staying behind. We opened our discussion with one such breakthrough research, and we will conclude with a couple more.

Click here to learn about the current state of quantum computing.

More On Quantum Computing Research

Google Quantum AI and collaborators published their research in Nature in December 2024. It came with the title Quantum Error Correction Below The Surface Code Threshold.²

The research addressed the issue of quantum error correction, a key path to practical quantum computing. By combining multiple physical qubits into a logical qubit, this approach exponentially suppresses the logical error rate as more qubits are added.

Resultantly, the researchers presented two below-threshold surface code memories on its newest generation of superconducting processors, Willow, a distance-7 code and a distance-5 code integrated with a real-time decoder.

The results were significant. The system maintained below-threshold performance when decoding in real-time, achieving an average decoder latency of 63 microseconds at distances of five up to a million cycles, with a cycle time of 1.1 microseconds. The researchers claimed that their research indicated that if scaled, device performance could realize the operational requirements of large-scale fault-tolerant quantum algorithms.

In 2022, keeping error correction in focus, IBM researchers explored a code called the gross code, a new kind of code that can store quantum information in an error-free way with a fraction of the hardware overhead. This could lead to error correction with significantly less overhead.

In a paper published in Nature, IBM specifically looked for fault-tolerant quantum memory with a low qubit overhead, high error threshold, and a large code distance. The company claimed that its mathematical analysis found concrete examples of qLDPC codes that met all the conditions of being fault-tolerant, having a quantum memory, and having a high error threshold, large code distance, and low qubit overhead.

The company claimed that its code fell into a family of codes called “Bivariate Bicycle (BB)” codes. They were going to shape not only IBM’s research going forward but also how we architect physical quantum systems.

Altogether, there is ample scope to realize steady progress in approaching the quantum advantage. Global public investments in quantum technology reached US$42 billion in 2023, with China leading the charts with an announced government investment of US$15.3 billion.

This was followed by Germany, the United Kingdom, the United States, and South Korea, among others. The fact that technologically advanced economies are investing more in Quantum Computing and related technology is a testimony to the fact that its scope is humongous. What we see now might only be the tip of the iceberg.

Click here for a list of top five quantum computing companies.