Researchers at ETH Zurich have reached a milestone in quantum computing when they demonstrated quantum teleportation in a solid-state circuit. In the process, they have also reached quantum speed record at 10,000 quantum bits per second.
The setup for the chip involved superconducting circuits in a configuration resembling a conventional computer chip.
Quantum teleportation is pairing entangled particles - one on one side of the chip and one on the other. Each of these particles has their own quantum states. And when entangled, changing the quantum state of one particle changes the other particle to the same state nearly instantaneously.
So although the name is inspired by the teleportation commonly used in fiction, quantum teleportation is limited to the transfer of information rather than matter.
A quantum bit (or "qubit") which holds the information, is capable of storing more information than classic bit. They are fabricated, initialized, controlled, read out and coupled to each other in simple circuits. This enables the realization of basic logic gates, the creation of complex entangled states, as well as the demonstration of algorithms or error correction.
This entanglement is very fragile. Until this date, the world record for quantum teleportation is a distance of about 88 miles. But if teleportation can occur in a solid state chip as the researchers have demonstrated, this would lead to the development of "quantum repeaters."
These quantum repeaters are similar to repeaters used in fiberoptic and radio transmissions, which strengthen signals. But here, quantum repeaters work on quantum teleportation signals over a network, enabling those signals to travel farther distances.
"Here we realize full deterministic quantum teleportation with feed-forward in a chip-based superconducting circuit architecture. We use a set of two parametric amplifiers for both joint two-qubit and individual qubit single-shot readout, combined with flexible real-time digital electronics."
Additionally, because the quantum teleportation on a chip is faster than other types of quantum teleportation seen to date, this milestone could also lead to improved quantum computers.