A superconducting-qubit quantum chip in package assembly developed and manufactured at the AWS ... [+]
Quantum computing, the cutting-edge technology that promises unprecedented computational power, has taken a significant leap forward with the unveiling of a groundbreaking quantum chip by Amazon Web Services.
“It's a custom-designed chip that's totally fabricated in house by our AWS quantum team,” said Peter Desantis, senior vice president of AWS utility computing products, during a keynote address in Las Vegas at AWS’s re:Invent conference for the global cloud computing community.
DeSantis said the state-of-the-art chip represents a major milestone in the quest for error-corrected quantum computers. “We've been able to suppress errors by 100x by using a passive error correction approach," he said.
Peter DeSantis, senior vice president, AWS
Quantum Bits: From Transistors to Qubits
Traditional computers rely on binary bits, represented by zeros and ones, to store and process information using transistors. In contrast, quantum computers utilize quantum bits, or qubits, which are quantum objects like electrons or photons. Unlike classical bits, qubits can exist in a superposition of states, allowing for simultaneous combinations of zeros and ones. This superposition, combined with the phenomenon of entanglement, enables quantum computers to perform complex computations at an exponential speed.
By harnessing the unique properties of qubits, quantum computers offer the potential to revolutionize industries and drive advancements in fields like agriculture, renewable energy, and more.
The Challenge of Noisy Qubits
Error Correction: A Crucial Challenge
In all computers, including quantum computers, errors occasionally occur. Classical computers utilize error correction techniques, such as ECC memory, to protect against “bit flips,” (0 to 1 or vice versa). However, quantum computers face a more daunting challenge due to their inherent sensitivity to noise from the environment. Qubits can experience errors in two dimensions: bit flips and phase flips (as if the qubit suddenly starts spinning in the opposite direction, which can lead to inaccuracies in quantum computations). To mitigate the effects of phase flip errors, quantum error correction techniques are employed. These techniques involve encoding information in multiple qubits in a way that allows detection and correction of phase flip errors.
The high error rates of qubits make them impractical for solving complex problems that require billions of error-free operations.
The Need For Improved Error Rates
Over the past 15 years, significant progress has been made in reducing qubit error rates. From one error every 10 quantum operations to one error every 1,000 operations, the error rates have improved by 100 times. However, despite this significant advancement, qubits are still too noisy to be practically useful for solving complex problems.
“The quantum algorithms that we get excited about require billions of operations without an error," said DeSantis. For example, Shor's algorithm, which could potentially break RSA encryption, requires a massive number of qubits that are currently beyond reach.
Quantum Error Correction: A Potential Solution
To address the challenge of noisy qubits, researchers have proposed various quantum error correction techniques. By encoding a block of physical qubits into a logical qubit, for example, it is possible to mitigate errors. However, due to the high error rates of current qubits, many physical qubits are required to create a single logical qubit. With today's error rates of 0.1%, each logical qubit needs thousands of physical qubits. This means we need further improvement in qubit error rates to make quantum error correction more efficient and scalable.
AWS's Breakthrough Quantum Chip
Revolutionizing Error Correction
The AWS Quantum Computing team has made significant strides in the development of a quantum chip that addresses the challenge of error correction more effectively. This custom-designed chip takes a unique approach to error correction by separating bit flips from phase flips. By utilizing a passive error correction approach, the chip has successfully reduced bit flip errors by a factor of 100, or 99%. This allows the active error correction to focus solely on phase flip errors, significantly improving the efficiency of quantum error correction.
Advancements In Hardware Efficiency
While the journey to error-corrected quantum computers is still in its early stages, the development of this quantum chip represents a crucial step forward. By enhancing hardware efficiency and scalability, DeSantis said the experimental results obtained with this prototype chip demonstrate the potential for achieving quantum error correction six times more efficiently than standard approaches.
In 2019, AWS established a center for quantum computing on a campus at Caltech, where Richard Feynman first proposed the idea of building a quantum computer in the early 1980s. Recognizing the limitations of classical computers in simulating quantum phenomena, Feynman imagined using quantum particles themselves to overcome these barriers. It was not until a decade later that mathematician Peter Shor astonished the scientific community with his discovery of a quantum algorithm for factoring numbers. Shor's algorithm, which offers exponential speedup over classical algorithms, demonstrated the potential of quantum computers to solve problems beyond simulating the quantum world.
From Labs To Engineering: Building Quantum Systems
In the following years, physicists began experimenting with small quantum systems consisting of two interacting qubits in laboratory settings. However, it was a significant breakthrough when scientists figured out how to produce qubits on the same electrical circuits used in classical computers. This marked the beginning of an engineering race to build practical and reliable quantum computers capable of solving complex problems. While the current quantum computers already boast hundreds or even thousands of qubits, there are significant challenges to overcome before they can truly change the world.
The Future of Quantum Innovation
AWS’s groundbreaking quantum chip may signify the beginning of an exciting new era of quantum innovation. The progress made in error correction and hardware efficiency brings us closer to a future where quantum computers can solve complex problems that were previously unimaginable.
