Researchers at Harvard University have achieved a significant milestone in quantum computing by developing a programmable logic quantum processor that can encode 48 logic qubits and perform hundreds of logic gate operations. Hailed as a potential turning point in the field, this advance marks the first demonstration of large-scale algorithm execution on an error-correcting quantum computer.

Harvard University’s breakthrough quantum computing features a new logical quantum processor with 48 logical qubits, enabling the execution of large-scale algorithms on error-corrected systems. The development, led by Mikhail Lukin, represents a major advance towards practical fault-tolerant quantum computers.

In quantum computing, a quantum bit or “qubit” is a unit of information, similar to a binary bit in classical computing. For more than two decades, physicists and engineers have shown the world that quantum computing is possible in principle by manipulating quantum particles such as atoms, ions, and photons to create physical qubits. I did.

But exploiting the strangeness of quantum mechanics for calculations is more complicated than collecting enough physical qubits, which are inherently unstable and prone to collapsing from their quantum states.

Logical qubit: the building block of quantum computing

The real coin of the realm in useful quantum computing are so-called logical qubits. This is a bunch of redundant, error-corrected physical qubits that can store information for use in quantum algorithms. Creating logical qubits as controllable units like classical bits is a fundamental hurdle for the field, and until quantum computers can reliably run on logical qubits, , it is generally accepted that the technology cannot really take off. To date, the best computing systems have demonstrated either: two logical qubits and one quantum gate operation – similar to just one operation code unit – between them.

A team led by quantum expert Mikhail Lukin (right) has achieved a breakthrough in quantum computing. Dr. Dorev Brufstein was a student in Lukin’s lab and the lead author of the paper.

Credit: Jon Chase/Harvard University Staff Photographer

Breakthrough in quantum computing at Harvard University

A team from Harvard University led by co-director Mikhail Lukin, Joshua and Beth Friedman Professor of Physics. Harvard Quantum Initiative has achieved an important milestone in the quest for stable and scalable quantum computing. For the first time, the team has created a programmable logic quantum processor that can encode up to 48 logic qubits and perform hundreds of logic gate operations. Their system is the first demonstration of large-scale algorithm execution on an error-corrected quantum computer, and heralds the early days of fault-tolerant, or guaranteed uninterruptible, quantum computing.

was announced on Nature, this research was conducted in collaboration with Marcus Greiner, the George Basmer Leverett Professor of Physics.colleague from Massachusetts Institute of Technology; and based in Boston QuEra Computing, a company founded on technology from Harvard University’s research labs.

Harvard University’s Office of Technology Development recently entered into a licensing agreement with QuEra for a patent portfolio based on innovations developed at the Lukin Group.

Lukin called the achievement a potential inflection point similar to the early days of the field of artificial intelligence, where long-theorized ideas of quantum error correction and fault tolerance are beginning to come to fruition.

“I think this is one of those moments where it’s clear that something very special is going to happen,” Lukin said. “While there are still challenges ahead, we expect this new advance to greatly accelerate progress toward large-scale, useful quantum computers.”

This breakthrough is based on several years of research into “quantum computing architectures.” neutral atomic arrangement, pioneered in Lukin’s lab and now commercialized by QuEra. The main component of the system is a block of ultracold, suspended rubidium atoms in which the atoms (the system’s physical qubits) move around and connect, or “entangle”, into pairs during calculations. Entangled pairs of atoms form gates, units of computational power.

Previously, the team demonstrated Low error rate for entanglement operations proving the credibility of their neutrality atom array system.

Impact and future directions

“This breakthrough is a masterpiece of quantum engineering and quantum design,” said Dennis Caldwell, acting deputy director of the National Science Foundation’s Mathematics and Physical Sciences Directorate, which supported the research through NSF’s Physics Frontiers Center and Quantum Leap Challenge Institute programs. says. “By using neutral atoms, the team has not only accelerated the development of quantum information processing, but also opened new doors to the search for large-scale logical qubit devices that could have transformative benefits for science and society as a whole. I opened the door.

Researchers are now using logic quantum processors to demonstrate parallel multiplexed control of entire patches of logic qubits using lasers. This result is more efficient and scalable than controlling individual physical qubits.

“We are seeking to mark a transition in the field by starting to test algorithms that use error-corrected qubits instead of physical qubits, enabling a path to larger devices. ,” said lead author Dorev Brubstein of the Griffin School of Arts and Sciences student in Lukin’s lab.

The team continues to work on demonstrating more types of operations with 48 logical qubits and configuring the system to run continuously, as opposed to manual cycles as it currently does.

Reference: “Logical quantum processors based on reconfigurable atomic arrays” Dolev Bluvstein, Simon J. Evered, Alexandra A. Geim, Sophie H. Li, Hengyun Zhou, Tom Manovitz, Sepehr Ebadi, Madelyn Cain, Marcin Kalinowski, Dominik Hangleiter, J. Pablo Bonilla Ataydes, Nishad Mascara, Iris Kong, Xun Gao, Pedro Salles Rodríguez, Tomas Karoliszyn, Julia Semeghini, Michael J. Galans, Markus Greiner, Vladan Vretić, Mikhail D. Lukin, December 6, 2023, Nature.
DOI: 10.1038/s41586-023-06927-3

This research was supported by the Defense Advanced Research Projects Agency through the Noisy Medium-Scale Quantum Devices Optimization Program. The Ultracold Atom Center, a National Science Foundation Physics Frontier Center. Army Research Office. and QuEra computing.

Source: scitechdaily.com