The quantum computing company Quantinuum recently announced a quantum computer it says outperformed a landmark Google computer’s result 100-fold.Quantum computers operate on quantum bits. Quantum bits are like ordinary computer bits, except their values can be both 0 and 1 simultaneously. Thanks to this quantum quirk, the computers can consider more solutions to a problem faster than a classical computer.
But quantum computers don’t look like ordinary computers. That’s because their qubits are often supercooled atoms, set up in an array. Cooled to such a degree, the atoms enter a quantum state. The moment any one of the qubits’ value is certain, the quantum state decoheres and the quantum operation falls apart. For that reason, quantum computers as they currently exist are only in dedicated research and laboratory settings.
To achieve the result, the Quantinuum team upgraded its H2-1 processor from a 32-qubit system to a 56-qubit system, vastly increasing its computing power. According to a Quantinuum release, its quantum computer also ran its algorithm with about 30,000 times less power than it would’ve taken a classical computer to run the operation.
Importantly, the Quantinuum computer achieved a new record for the cross entropy benchmark, a metric used to compare the performance of different quantum computers. The benchmark measures the power of the quantum system; the noisier the system, the worse your results are. Google’s 2019 score on the cross entropy benchmark was ~.002; H2-1’s score was ~.35.
“The experiment that we describe seems impossible to solve with standard physics, which obeys the normal arrow of time,” David Arvidsson-Shukur, a quantum physicist at the University of Cambridge and the study’s lead author, told Gizmodo at the time. “Thus, it appears as if quantum entanglement can generate instances which effectively look like time travel.”Quantinuum has also run the news circuit .