SAN FRANCISCO, Nov 20 (Reuters) - IBM ( IBM ) and Cisco

Systems ( CSCO ) on Thursday said they plan to link quantum

computers over long distances, with the goal of demonstrating

the concept is workable by the end of 2030.

The move could pave the way for a quantum internet, though

executives at the two companies cautioned that the networks

would require technologies that do not currently exist and will

have to be developed with the help of universities and federal

laboratories.

Quantum computers hold the promise of solving problems in

physics, chemistry and computer security that would take

existing computers thousands of years. But they can be

error-prone and making a reliable one is a challenge that IBM ( IBM ),

Alphabet's Google and others are pursuing. IBM ( IBM ) is seeking to

have an operational machine by 2029.

Earlier this year, Cisco ( CSCO ) opened a lab to investigate how

to connect quantum machines.

The challenge begins with a problem: Quantum computers like

IBM's ( IBM ) sit in massive cryogenic tanks that get so cold that atoms

barely move. To get information out of them, IBM ( IBM ) has to figure

out how to transform information in stationary "qubits" - the

fundamental unit of information in a quantum computer - into

what Jay Gambetta, director of IBM Research and an IBM ( IBM ) fellow,

told Reuters are "flying" qubits that travel as microwaves.

But those flying microwave qubits will have to be turned

into optical signals that can travel between Cisco ( CSCO ) switches on

fiber-optic cables. The technology for that transformation -

called a microwave-optical transducer - will have to be

developed with the help of groups like the Superconducting

Quantum Materials and Systems Center, led by the Fermi National

Accelerator Laboratory near Chicago, among others.

Along the way, Cisco ( CSCO ) and IBM ( IBM ) will also publish open-source

software to weave all the parts together.

"We are looking at this end-to-end as a system ... rather

than two discrete road maps," said Vijoy Pandey, senior vice

president of Cisco's ( CSCO ) Outshift innovation incubator. "We are

solving it jointly, which has a much better chance of this thing

going in the same direction."