“We’re making uncertainty an ally and embracing it,” said Dr. Spiropulu.
To reach their full potential, quantum computers need thousands of working qubits and another million “error correction” qubits. Google hopes to reach such a goal by the end of the decade, who is also part of Dr. Spiropulu.
The Caltech physicist and Nobel laureate Richard Feynman once predicted that the ultimate use of this quantum power could be to explore quantum physics itself, as in the wormhole experiment.
“I’m excited to see researchers make Feynman’s dream come true,” said Dr. Cousins.
The wormhole experiment was performed on a version of Google’s Sycamore 2 computer, which has 72 qubits. Of these, the team used only nine to limit the amount of interference and noise in the system. Two were reference qubits, playing the role of input and output in the experiment.
The seven other qubits contain the two copies of the code that describes a “sparsified” version of an already simple model of a holographic universe called SYK, named after its three creators: Subir Sachdev of Harvard, Jinwu Ye of Mississippi State University, and Alexei Kitaev from Caltech. Both SYK models were packed in the same seven qubits. In the experiment, these SYK systems played the role of two black holes, one by distorting the message into nonsense – the quantum equivalent of swallowing it – and the other by causing it to pop out again.
“Into this we throw a qubit,” said Joseph Lykken, leader of the Fermilab Quantum Institute and an author of the Nature paper; he was referring to the input message – the quantum analog of a series of ones and zeros. This qubit interacted with the first instance of the SYK qubit; its meaning was distorted into random noise and it disappeared.
Then, in a tick of the quantum clock, the two SYK systems connected and a jolt of negative energy passed from the first system to the second, briefly holding the latter open.
The signal then reappeared in its original, unencoded form — in the ninth and final qubit attached to the second SYK system, which represented the other end of the wormhole.
