Washington, May 27 : A team of physicists has been the first to demonstrate a crucial element for a future functioning quantum computer - repetitive error correction.

As quantum systems are even more sensitive to environmental disturbances than classical systems, a quantum computer requires a highly efficient algorithm for error correction.

The team, led by Philipp Schindler and Rainer Blatt, from the Institute for Experimental Physics of the University of Innsbruck and the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences (IQOQI), has now demonstrated such an algorithm experimentally.

"The difficulty arises because quantum information cannot be copied. This means that we cannot save information repeatedly and then compare it," Schindler explained.

Therefore, the physicists use one of the peculiarities of quantum physics and use quantum mechanical entanglement to perform error correction.

The Innsbruck physicists demonstrate the mechanism by storing three calcium ions in an ion trap. All three particles are used as quantum bits (qubits), where one ion represents the system qubit and the other two ions auxiliary qubits.

"First we entangle the system qubit with the other qubits, which transfers the quantum information to all three particles," Schindler explained.

"Then a quantum algorithm determines whether an error occurs and if so, which one. Subsequently, the algorithm itself corrects the error," he said.

After having made the correction, the auxiliary qubits are reset using a laser beam.

"This last point is the new element in our experiment, which enables repetitive error correction," Blatt said.

"Some years ago, American colleagues demonstrated the general functioning of quantum error correction. Our new mechanism allows us to repeatedly and efficiently correct errors," he stated.

Schindler added: "For a quantum computer to become reality, we need a quantum processor with many quantum bits. Moreover, we need quantum operations that work nearly error-free. The third crucial element is an efficient error correction."

The researchers have published their findings in the scientific journal Science. (ANI)