Quantum computers: Instantaneous two-way communication between superconducting nodes is possible

In the fascinating world of science, a team of researchers at the University of Chicago has made a quantum leap into the future of communication. They created a kind of "bridge" between two distant points, using something that seems to come out of a science fiction book: superconducting qubits. But what does all this mean? Imagine having two computers that can talk to each other through a channel, transmitting messages instantly and securely, as if by magic. This is the heart of quantum communication and the future of quantum computers.

A testbed for quantum communications between quantum computers

Quantum computers
Credits: Joel Grebel, Haoxiong Yan, Ming-Han Chou, Gustav Andersson, Christopher R. Conner, Yash J. Joshi, Jacob M. Miller, Rhys G. Povey, Hong Qiao, Xuntao Wu, and Andrew N. Cleland
Phys. Rev. Lett. 132 , 047001 – Published 25 January 2024

Quantum communication testbeds represent a milestone on the path to understanding and applying quantum principles to the transmission of information. Researchers at the University of Chicago have demonstrated a testbed for superconducting circuits capable of achieving bidirectional multi-photon state transfer, marking a significant breakthrough in this area.

This technology not only opens new frontiers in quantum research, but also establishes a solid foundation for the development of safer and more efficient communication systems. Through the use of remote superconducting nodes and precise manipulation of wave packets in the time domain, scientists are now able to explore new communication protocols, bringing the future of a global quantum network closer.

Qubits: not just zeros and ones

Quantum communication represents the transfer of information using the laws of quantum mechanics, allowing a higher data processing speed than traditional systems. The protagonists of this story are qubits, the fundamental units of information in the quantum world. Unlike traditional bits, which can be 0 or 1, qubits can be both at the same time, thanks to a property called superposition. This feature allows you to process information in ways that traditional computers can't even imagine.

The research conducted in Chicago opens new perspectives on the use of superconducting circuits for the efficient communication of complex quantum states, a goal that until recently seemed distant.

Superconductors: the superheroes of the quantum world

The researchers used superconducting nodes, materials that at extremely low temperatures conduct electricity without resistance or energy loss. By connecting these quantum superheroes with a transmission line, they created a channel to “teleport” quantum information from one point to another without any traditional physical connection.

Resonators: the archivists of the quantum world

A crucial role in this process is played by resonators, devices capable of storing quantum states, acting as a sort of super-advanced memory . These resonators can contain very complex information, allowing a much larger amount of data to be transmitted than traditional methods. The innovative use of superconducting resonators to send and receive data could significantly increase the bandwidth of quantum communications.

Quantum computers: a two-way conversation between qubits

Quantum computers
Credits:Joel Grebel, Haoxiong Yan, Ming-Han Chou, Gustav Andersson, Christopher R. Conner, Yash J. Joshi, Jacob M. Miller, Rhys G. Povey, Hong Qiao, Xuntao Wu, and Andrew N. Cleland
Phys. Rev. Lett. 132 , 047001 – Published 25 January 2024

Published in Physical Review Letters, the work of the Chicago researchers builds on previous studies that have demonstrated the possibility of generating remote entanglement and transmitting complex quantum states. “In our new study, we aimed to transmit quantum states representing multiple qubits at once,” says Andrew Cleland, co-author of the study.

As mentioned above, the real magic happened when they demonstrated that communication could happen in both directions at once, sending complex quantum states, as if qubits were “talking” to each other in a language unknown to the classical world.

The experiment involved the use of superconducting qubits and tunable resonators connected across a 2-meter-long transmission line. Using advanced techniques, the team managed to program various quantum states and transmit them effectively. This bidirectional transmission opens up new possibilities for quantum communication, demonstrating the feasibility of transmitting complex quantum states beyond simple photons. This not only challenges our concept of communication but also opens up endless possibilities for the future of cryptography, computing and cybersecurity .

“Our system can transmit in both directions equally effectively,” Cleland explained, highlighting the flexibility and innovation of the design used. Bidirectional transmission of photons at a single microwave frequency and simultaneous transmission of two-photon Fock states represent just some of the possibilities revealed by this study.

Quantum computers: towards a quantum connected future

This experiment isn't just an impressive lab trick; it is proof that we can build communications systems that can transfer complex information efficiently and securely over remote distances. Imagine a future where quantum computers, spread across the world, can instantly share data and resources, creating a distributed computing network of unimaginable power.

In an era marked by an exponential increase in cybercrime, the promise of bulletproof communication is more appealing than ever. This technology could not only provide impregnable security systems for banks and government secrets but could also protect personal communications from prying eyes.

The research conducted by the University of Chicago is not just a breakthrough in quantum communication; it is a leap towards a future in which the limits of traditional physics are overcome, opening the doors to innovations that we can only dream of today. This journey into the heart of the quantum world shows us that, when it comes to science and technology, the future is more exciting and accessible than we thought.

The article Quantum computers: instant bidirectional communication between superconducting nodes is possible was written on: Tech CuE | Close-up Engineering .