Quantum computers have the potential to tackle some of the most complex problems in the world, but the key challenge lies in scaling them up. A new modular design for quantum chips could be the solution to building large-scale quantum computers more effectively.
Despite significant advancements in building larger quantum processors, the technology still lags far behind conventional computer chips in terms of scale. Most leading quantum computers, which are based on superconducting qubits, have only recently surpassed the 1,000-qubit milestone due to the fragility of qubit technologies and the intricate control systems required to manipulate them.
Engineers at MIT and the MITRE Corporation have proposed a new platform that could offer a more scalable solution. In a recent paper published in Nature, they demonstrated the integration of over 4,000 qubits made from diamond defects onto an integrated circuit for control. This “quantum systems-on-a-chip” approach could pave the way for connecting multiple chips via optical networking to create large-scale quantum computers.
The use of diamond color centers as qubits shows promise due to their long quantum state retention and ability to be entangled with distant qubits using light signals. These solid-state systems are also compatible with conventional electronics manufacturing processes. However, the non-uniform nature of diamond color centers poses a challenge in terms of controlling large numbers of qubits.
To address this challenge, the researchers developed a novel fabrication technique to create quantum microchiplets featuring multiple color centers. By tuning the qubits’ frequencies using voltages applied by the chip, they were able to overcome the inhomogeneity of the diamond color centers and achieve resonance with individual atoms for communication.
While the researchers have yet to demonstrate actual computing capabilities with the device, their innovative approach shows promise for achieving qubit densities comparable to those in conventional electronics. This highly scalable modular architecture could bring us closer to the millions of qubits necessary to fully leverage the power of quantum computing.
Although other research teams are also working on assembling large numbers of qubits, such as the recent report of 6,100 “neutral-atom” qubits by Caltech researchers, the modular architecture presented in this study offers significant potential for advancing quantum technology. With further development, this approach could help unlock the true potential of quantum computing.
[Image Credit: Sampson Wilcox and Linsen Li, RLE]
