This network would use special communication channels designed to communicate the quantum states of qubits, paving the way for distributed quantum computing. Such advances could exponentially increase the power of quantum computers, which are already considered very promising.

How will it work?

The initiative draws inspiration from methods used in gravitational wave observatories, where qubits must transmit in the vacuum of space to maintain their quantum state. The ambitious project is funded by the US military and other government agencies, a testament to its strategic importance.

Quantum Internet promises not only a completely secure connection that cannot be hacked without being detected, but also a significant leap in computing power. Distributed quantum computing solves the current challenges of scaling quantum platforms, which are limited by physical size and number of qubits. By redistributing the computational load, the performance of quantum systems can be significantly increased.

Proposed map of US quantum network / Photo: Jiang Group / University of Chicago

Problem and solution

Researchers have already shown that it is possible to exchange quantum states over long distances using photonic coding. This method would allow quantum states to be transmitted through conventional optical fibers and lasers, air, vacuum, and even satellites. However, current transmission speeds are low and optical fibers suffer from significant attenuation.

To overcome these limitations, scientists from the University of Chicago used the experience of gravitational wave observatories that use three-kilometer tunnels held in high vacuum (10^-11 atmospheres).

In these tunnels, photons travel vast distances in response to gravitational waves. Similarly, quantum information encoded in the states of photons can be transmitted for hundreds or even thousands of kilometers if a system of focusing lenses is used along the entire path.

The proposed quantum internet network would consist of 20 cm diameter vacuum tubes equipped with lenses focusing every few kilometers. Calculations show that the system could operate effectively at an average vacuum level of 10^-4 atmospheres.

The next phase of the project involves conducting an economic feasibility study, but the researchers stress that the funding will not be a deterrent to building a high-speed quantum network.