As technological efforts continue to advance, US researchers have taken a massive step forward in quantum computing, developing a novel interconnect device that paves the way for scalable, all-to-all communication between superconducting quantum processors.
Indeed, unlike conventional architectures, the device created by the scientists at the Massachusetts Institute of Technology (MIT) allows every processor within a quantum network to communicate directly, according to a report by the organization from March 21.
As such, it greatly reduces compounding error rates that have been a more regular occurrence in traditional setups, considering the fact that they rely on point-to-point connections where quantum data travels sequentially through various network nodes.
How MIT’s quantum computer breakthrough solves this
Specifically, the discovery revolves around a superconducting wire or waveguide that efficiently transfers microwave photons (the carriers of quantum information in this case) between processors. In its recent demonstration, the MIT team successfully connected two quantum modules, each containing four qubits that interface with the larger quantum system.
By sending photons back and forth on demand, the researchers were able to demonstrate remote entanglement, a phenomenon where two distant quantum processors share a correlated quantum state despite not being physically connected, which is key to creating a high-fidelity, distributed quantum network.
As Aziza Almanakly, an electrical engineering and computer science graduate student in the Engineering Quantum Systems group of the Research Laboratory of Electronics (RLE) and lead author of a paper on the interconnect, explained:
“In the future, a quantum computer will probably need both local and nonlocal interconnects. Local interconnects are natural in arrays of superconducting qubits. Ours allows for more nonlocal connections. We can send photons at different frequencies, times, and in two propagation directions, which gives our network more flexibility and throughput.”
The team further enhanced the system using a reinforcement learning algorithm that ‘predistorted’ the photons, maximizing the photon absorption efficiency at over 60%, which is critical for reliably generating remote entanglement and a foundational requirement for distributed quantum computing.
As it happens, the innovative architecture not only enables powerful entanglement between quantum processors but also opens the door to constructing a large-scale quantum computer from smaller modules. Researchers noted that such modularity could allow parallel operations across distant qubits, a promising prospect for future quantum networks.
In the words of a graduate student in the EQuS Group and the study’s co-author, Beatriz Yankelevich:
“Generating remote entanglement is a crucial step toward building a large-scale quantum processor from smaller-scale modules. Even after that photon is gone, we have a correlation between two distant, or ‘nonlocal,’ qubits. Remote entanglement allows us to take advantage of these correlations and perform parallel operations between two qubits, even though they are no longer connected and may be far apart.”
Conclusion
All things considered, the study has demonstrated that even photons face obstacles like joints and wire bonds, which can distort them and limit the absorption efficiency of the receiving module. However, carefully shaped pulses can overcome these challenges to maintain efficient communication between modules.
Meanwhile, the European Union (EU), more precisely the European Quantum Communication Infrastructure (EuroQCI), is taking major steps towards advancing Europe’s quantum capabilities, including the integration of quantum-based systems into existing communications infrastructures.
ReadNext
