IBM engineers have successfully demonstrated the transfer of quantum information between two processors with approximately 99% accuracy. The experiment utilized four superconducting connections, each 80 cm long, to link the chips.
The setup involved two 120-qubit IBM Quantum Nighthawk processors connected by aluminum coaxial cables operating at microwave frequencies of about 5 GHz. The connections were secured using indium-indium pressure contacts at room temperature before being placed in a cryogenic system.
Researchers performed two-qubit CZ operations between the chips, achieving an average accuracy of 94.75% and a peak of 96.42%. The system remained functional after three thermal cycles of heating and cooling.
The experiment validated the L-coupler technology for scaling quantum systems. IBM plans to leverage this modular approach to build the Starling quantum supercomputer, aiming for a practical system by 2029.
