Fujitsu and RIKEN have jointly developed a 256-qubit quantum computer, which builds on the 64-qubit version launched at the end of 2023. Thanks to new high-density implementation techniques, computing power has now quadrupled.
The new quantum computer is a breakthrough in developing practical applications of quantum technology. Researchers and companies can tackle more complex challenges with four times the number of qubits. Examples include analyzing larger molecules and implementing advanced error correction algorithms.
Technical challenges
One of the biggest obstacles to scaling up quantum computers is cooling within the dilution refrigerator. Fujitsu and RIKEN have addressed this challenge with a high-quality implementation and advanced thermal design. This allows all 256 qubits to operate in the same cooling unit previously used for the 64-qubit system.
The new machine uses a scalable 3D interconnection structure in which 4-qubit cell units are arranged in a three-dimensional configuration. This enables efficient scaling without complex redesigns. The system uses the same cell designs as its 64-qubit predecessor, confirming the scalability of this architecture.
The optimized balance between heat generation from control circuits and cooling capacity is an important technical aspect. This balance allows the system to maintain the ultra-high vacuum and extremely low temperatures required for quantum computing.
The quantum computer will be available worldwide by July.