IBM Links Quantum Chips with 99% Transmission Accuracy
The experiment lays the foundation for scaling computations beyond a single chip and implementing more complex error correction codes
The study used two IBM Quantum Nighthawk R1 processors installed in a single cryogenic system. Four l-couplers were connected between them, each with an 80-centimeter-long aluminum cable; the connectors were installed after the processors were mounted.
The maximum accuracy of quantum state transfer reached 99.3%, with an average figure of 99%. Researchers also performed inter-module two-qubit CZ operations, with their average accuracy across four channels equaling 94.75%.
Using these operations, IBM achieved entangled states, including by simultaneously engaging two l-couplers. This scheme enables the transmission of quantum information between processors and is viewed by the company as the foundation for a modular architecture.
The design is compatible with IBM Quantum Nighthawk processors and is intended for scaling up to IBM Quantum Starling and subsequent systems. IBM plans to improve the reproducibility of connectors, reduce error levels, and connect more channels to more complex processors.
