Quantum systems correct themselves

November 28, 2017

Quantum devices allow us to accomplish computing and sensing tasks that go beyond the capabilities of their classical counterparts. However, protecting quantum information from being corrupted by errors is difficult.

An international team of researchers from Innsbruck, Harvard, Copenhagen and Waterloo put forward a new method to protect quantum information stored in trapped ions. In their new proposal, the authors use dissipation (i.e. the interaction of a quantum system with its environment) to correct quantum states. Dissipation is typically considered harmful, but as demonstrated by Florentin Reiter and colleagues, it can be tweaked to work in a quantum engineer's favor.

Standard schemes are performed by applying a sequence of gates in a logical quantum circuit and rely on measurements by classical devices. The new dissipative approach does not require a logical circuit and dispenses also with measurements. "The whole error correcting process happens autonomously at the microscopic level, such that systems can correct themselves," said co-author Christine Muschik, of the Department of Theoretical Physics at the University of Innsbruck and the Institute of Quantum Optics and Quantum Information at the Austrian Academy of Sciences.

The new approach has important practical applications for high-precision measurements. "We showed how the new dissipative correction mechanism can be used to enhance the precision for sensing ," Muschik said. These results open new avenues for improving high-precision sensing schemes with trapped ions and constitute a stepping stone towards the paradigm of self-correcting processing.

Explore further: Ion qubits offer early glimpse of quantum error detection

More information: F. Reiter et al. Dissipative quantum error correction and application to quantum sensing with trapped ions, Nature Communications (2017). DOI: 10.1038/s41467-017-01895-5

Related Stories

Ion qubits offer early glimpse of quantum error detection

November 9, 2017

Computers based on quantum physics promise to solve certain problems much faster than their conventional counterparts. By utilizing qubits—which can have more than just the two values of ordinary bits—quantum computers ...

Researchers develop data bus for quantum computer

November 6, 2017

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass ...

Turning ions into quantum cats

September 29, 2017

In Schrödinger's famous thought experiment, a cat seems to be both dead and alive—an idea that strains credulity. These days, cats still don't act this way, but physicists now regularly create analogues of Schrödinger's ...

Blind quantum computing for everyone

August 11, 2017

(Phys.org)—For the first time, physicists have demonstrated that clients who possess only classical computers—and no quantum devices—can outsource computing tasks to quantum servers that perform blind quantum computing. ...

New tool for characterizing quantum simulators

September 6, 2017

Physicsts are developing quantum simulators, to help solve problems that are beyond the reach of conventional computers. However, they first need new tools to ensure that the simulators work properly. Innsbruck researchers ...

Recommended for you

Single-photon detector can count to four

December 15, 2017

Engineers have shown that a widely used method of detecting single photons can also count the presence of at least four photons at a time. The researchers say this discovery will unlock new capabilities in physics labs working ...

Real-time observation of collective quantum modes

December 15, 2017

A cylindrical rod is rotationally symmetric - after any arbitrary rotation around its axis it always looks the same. If an increasingly large force is applied to it in the longitudinal direction, however, it will eventually ...

A shoe-box-sized chemical detector

December 15, 2017

A chemical sensor prototype developed at the University of Michigan will be able to detect "single-fingerprint quantities" of substances from a distance of more than 100 feet away, and its developers are working to shrink ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.