Physicists create ‘smallest, nastiest wormhole you can imagine’

“Let’s make uncertainty an ally and embrace it,” said Dr. Spiropulu.

To reach their full potential, quantum computers will need thousands of working qubits and another million “error correcting” qubits. Google hopes to achieve that goal by the end of the decade, according to Hartmut Neven, head of the company’s Quantum Artificial Intelligence Laboratory in Venice, California, who is also part of Dr. Spiropulus.

Caltech physicist and Nobel laureate Richard Feynman once predicted that the ultimate use of this quantum power might be to investigate quantum physics itself, as in the wormhole experiment.

“I’m excited to see that researchers can live Feynman’s dream,” said Dr. Neven.

The wormhole experiment was conducted on a version of Google’s Sycamore 2 computer, which has 72 qubits. Of these, the team only used nine to limit the amount of interference and noise in the system. Two were reference qubits, which played the role of input and output in the experiment.

The other seven qubits contained the two copies of the code describing a “sparsified” version of an already simple model of a holographic universe called SYK, named after its three creators: Upload Sachdev from Harvard, Jinwu Ye from Mississippi State University and Alexei Kitaev from Caltech. Both SYK models were packed into the same seven qubits. In the experiment, these SYK systems played the role of two black holes, one mixing the message into nonsense, the quantum equivalent of swallowing it, and then the other popping back out.

“We throw a qubit in there,” Dr Lykken said, referring to the input message – the quantum analogue of a series of ones and zeros. This qubit interacted with the first copy of the SYK qubit; its meaning shuffled into random noise and disappeared.

Then, in one tick of the quantum clock, the two SYK systems were connected and a shock of negative energy passed from the first system to the second, briefly opening the second.

The signal then reappeared in its original unencoded form: in the ninth and final qubit, connected to the second SYK system, which represented the other end of the wormhole.