An international research group has developed and implemented a new protocol that allows for the protection and the correction of the fragile quantum information in case of errors due to qubit loss.
When quantum computers elaborate the data, some qubits can be completely lost from the quantum registers or they can transition to unwanted electronic states. The outcome of both these processes is a loss that may render the quantum processor useless. For this reason, devising theory-based and experimental techniques that can analyse and mitigate the consequences of these errors is extremely important.
The research group developed an effective theoretical approach to the issue and managed to show that the information stored in a register with some qubits can be protected and fully retrieved in case one of these qubits gets lost.
Then, the research group implemented this protocol in a real-life quantum processor. This is not easy at all, however. Indeed, for assessing whether a qubit is lost, a direct measurement of it will destroy all the information that is contained in the quantum register.
The research group came up with the solution of using an additional qubit that functions as a probe and can assess the presence or absence of other qubits without altering the computing process. This idea worked, allowing the researchers to successfully test their protocol in real-time. (SciTechDaily)
This research has been published in Nature.