Physicists at the Swiss Federal Institute of Technology Zurich [ETH Zurich] have for the first time successfully teleported information in a solid-state system, similar to a computer chip. The major achievement of this study is that the information is not stored and processed based on the laws of classical physics, like conventional computer chips, but on those of quantum physics. The experimental device developed could serve as the basis for future quantum computing platforms.
In telecommunications, information is transported using a carrier (e.g., an electromagnetic pulse). However, quantum teleportation does without a carrier. The information disappears from the sender and instantly appears on the receiver. This is possible due to quantum entanglement, one of the most intriguing phenomena in quantum mechanics.
When two objects are entangled, they share a peculiar connection produced by the laws of quantum mechanics: every change made to one object will be produced as an instantaneous effect on the other one, regardless of the distance between them.
The ETH physicists successfully teleported information between two entangled quantum bits [qubit]1 across a distance of about six millimetres, from one corner of a chip to the opposite one.
In the experiment, the physicists spaced three micron-sized electronic circuits in a 7×7 mm chip. Two of the circuits were used as the sender mechanism and the third one as the receiver. To access the quantum properties of the system, they cooled down the chip to temperatures very close to the absolute zero. The entanglement between the two parts was made using controlled pulses of microwave-photons. At that point, the ETH team encoded some information into the qubits in the sending circuits and then measured the state of the qubits in the receiver, finding that the teleportation was successful.
The device turned out to be much more reliable than most previous systems and also much faster, being able to teleport 10,000 qubits per second.
The small distance over which the physicists have teleported information seems to be short in comparison with previous experiments, which sent information over hundreds of kilometres using visible light in an optical system for teleportation. However, the ETH experiment managed to reliably teleport information for the first time in a system consisting of electronic circuits, which are an important element for the eventual construction of quantum computers in the future.
In a next step, the physicists will try to teleport information from one chip to another. Looking further ahead, their goal will be to explore whether quantum communication can be realised over longer distances with electronic circuits, more comparable to those achieved today with optical systems.
- A quantum bit [qubit] is a unit of quantum information used in quantum computing. Unlike a bit, which normally has a value of either 0 or 1, a qubit can be 0, 1, or a superposition of both. [↩]