MIT develops efficient wireless interconnect for quantum processors

Researchers from the Massachusetts Institute of Technology (MIT) have developed a new wireless technology for connecting quantum computers' qubits. These qubits operate at very low temperatures, but traditional connections can introduce too much heat, making them impractical for large-scale use. Current methods use coaxial cables and optical connections that generate unwanted heat and noise. This makes it difficult to scale quantum systems, which ideally should connect thousands or millions of qubits. The new system uses a wireless terahertz (THz) cryogenic interconnect made with standard semiconductor technology. It minimizes heat transfer while effectively carrying quantum information. Jinchen Wang, the first author of the study, explained that existing cables add about 1 milliwatt of heat to the system, which limits the number of qubits that can be managed. For example, a 50-qubit quantum computer can have more than 500 cables connected, making expansion challenging. To solve this, the researchers introduced backscatter communication. This allows THz signals to be sent from outside the cryogenic environment, where power consumption is less of a concern. The signal is then modulated with data from the qubits and sent back, similar to how a mirror reflects light. Initial tests show that this new interconnect outperforms commercial microwave cables regarding energy efficiency. It is expected to support the larger deployment of quantum computers and can be made affordably using existing technologies. Looking ahead, the researchers plan to develop a multi-channel system that will reduce heat further and improve scalability. They hope this innovation will be key to creating practical quantum computing systems in the coming years.