Google announces ‘breakthrough’ in quantum computing  

Scientists at Google claim they have created an algorithm that can solve problems on a quantum processor 13,000 times faster than the world’s fastest supercomputers. 

The algorithm, called Quantum Echoes, operates at the extreme edge of quantum computing. Google claims that the Echoes algorithm, which runs on its Willow chip, achieves quantum advantage. Quantum advantage is when a quantum computer can run a computation more accurately and efficiently than a "classical" computer. 

“Quantum Echoes can be useful in learning the structure of systems in nature, from molecules to magnets to black holes, and we’ve demonstrated it runs 13,000 times faster on Willow than the best classical algorithm on one of the world’s fastest supercomputers,” said Google.  

Quantum Echoes works by sending a specific signal into a quantum system and then “listening” for the “echo” that comes back. The process is like a sonar radar, scanning the bottom of the seafloor and then bouncing sound waves back that give an outline of the seabed below. 

This allows for the algorithm to model the complex structure of a molecule, opening the door to future discoveries in medicine and other sciences. 

“This is the first time in history that any quantum computer has successfully run a verifiable algorithm that surpasses the ability of supercomputers,” Google said. “Quantum verifiability means the result can be repeated on our quantum computer — or any other of the same calibre — to get the same answer, confirming the result. This repeatable, beyond-classical computation is the basis for scalable verification, bringing quantum computers closer to becoming tools for practical applications.” 

Michel Devoret, the chief scientist at Google’s quantum AI unit, led the team who made the algorithm. Devoret, who won the Nobel Prize for physics earlier this month for his work in quantum research, said the innovation is a “new step” towards full-scale quantum computing. 

Quantum computers work by encoding their data differently from “classical” computers. On a “classical” computer, data is encoded in bits, which are represented as either a 0 or a 1.  

But in quantum computing, the data is stored in qubits. Qubits, through a complex property of quantum physics called superposition, can be in several states at the same time. This means that a qubit can be both a 0 and a 1 at the same time, vastly increasing the speed of calculations possible on a quantum computer. 

The theory for quantum computing is still a theory, as the technology that would allow qubits to operate in a stable environment and produce reliable outcomes is a long way off. Despite this, Google claims that this algorithm is a “significant” step down that long road towards full quantum computing.