D-Wave demonstrates fast, high-fidelity entangling gate for dual-rail cavity qubits to simplify quantum error correction
D-Wave has successfully demonstrated a new two-qubit entangling gate for dual-rail cavity qubits, a significant milestone in the development of gate-based quantum computing. The company's research, published in Nature, shows that the 'Swap–Wait–Swap' (SWS) gate allows two qubits to be entangled in approximately 500 ns while preserving the unique error hierarchy of the dual-rail system. In this architecture, photon loss—referred to as an erasure—is the most frequent error and is easily detectable, followed by dephasing errors, with bit-flips being extremely rare. By maintaining this structured noise, the SWS gate enables more compact and efficient error-correction codes compared to traditional methods. Trevor Lanting, a representative for D-Wave, noted that the gate is fast enough for practical use and preserves the high fidelity of the dual-rail devices. While the system currently faces some calibration drift as gate depth increases, D-Wave plans to scale the technology to 181 dual-rail qubits by 2028 to test various surface code error-detection schemes.