Technology prevents errors in quantum computers


The research group developed and implemented a new protocol that allows for the preservation and correction of fragile quantum information in case of errors due to qubit loss. Sincerely: Harald Ritts / IQOQI

Even quantum computers make mistakes. Their computing capability is extraordinary, far exceeding that of classical computers. The reason for this is that circuits in quantum computers are based on quants, which can represent not only zeros or masses, but also superposition of both states using the principles of quantum mechanics. Despite its great potential, qubits are extremely fragile and prone to errors due to interactions with the external environment.


To address this important issue, an international research group developed and implemented a new protocol that protects fragile quantities of information and corrects errors caused by qubit loss. This research group published the results of its study Nature.

“The development of fully functioning quantum processors is still a major challenge for scientists around the world,” explains David Vodola who is one of the study’s authors as well as a researcher at the University of Bologna. “This research allowed us, for the first time, to implement a protocol that can detect at the same time and at the same time, correct errors due to qubit losses. This capability is largely quantum quantified in the future May prove necessary for the development of computers. ”

We know that quantum processors show a certain tolerance against computational errors. But we know very little about how to prevent and correct errors due to any complete or partial loss.

When quantum computers expand data, some quantum can be lost from quantum registers altogether or they may transition to unwanted electronic states. Both of these processes result in a disadvantage that may render the quantum processor useless. For this reason, formulating theory-based and experimental techniques that analyze and minimize the consequences of these errors is extremely important.

“To solve this problem, our research group first developed an effective theoretical approach on this issue,” says Vodola. “We managed to show that with a few quibets the information kept in the register could be preserved and fully recovered in the event of one of these being lost.”

Then, the research group implemented this protocol in real-life quantum processors. Although it was not easy. In fact, a direct measurement will destroy all the information contained in the quantum register to assess whether a qubit is lost.

The research group came up with a solution to use an additional qubit that serves as a probe and can assess the presence or absence of other qubits without changes in the computing process. The idea worked, allowing researchers to successfully test their protocols in real-time.

“We are pleased with the results of this test on a stranded ion quantum processor from the University of Innsbruck,” Vodola confirms. “The same protocol can be implemented in different quantum computer architectures that are currently being developed by other research centers or private institutions.”


The study enables to predict the computational power of early quantum computers


more information:
Experimental deterministic correction of klebit loss, Nature (2020). DOI: 10.1038 / s41586-020-2667-0, www.nature.com/articles/s41586-020-26-0-0

Provided by Università di Bologna

Quotes: Technology Prevents Errors in Quantum Computers (2020, 9 September) Retrieved 10 September 2020 from https://phys.org/news/2020-09-technique-errors-quantum.html

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