IonQ Quantum Computers: Clear to Scale

A leading candidate for scalable quantum computers is based on individual atomic ion qubits, suspended and isolated with electric fields produced from electrodes etched on an ion trap chip, and individually addressed with laser beams. The qubits, represented by internal atomic energy levels, are not affected by the trapping forces, and confinement times can be indefinitely long. Because the qubit levels are excellent atomic clocks, their idle performance is essentially perfect, with indefinitely long T1 decay and T2 coherence times. In addition, trapped ion qubits are replicable to a level of accuracy much better than needed, and can thus be scaled without accumulating errors. External classical control fields, in the form of gated laser beams, allow reconfigurable all-to-all entangling quantum logic gate operations with up to about 100 qubits. Scaling to more than 1000 qubits can be accomplished by shuttling individual ions through a single chip. Scaling to arbitrarily large numbers of qubits, even up to 1,000,000 or more qubits will take the form of a modular photonic network, much like classical CPUs are fabricated today. This clearly defined roadmap does not require any breakthroughs in physics, but requires a serious effort in systems engineering and integrated optics. Perhaps the most attractive feature of this architecture is that there are no hardwires, as every quantum gate and connection is defined in software. At IonQ we are pursuing such a path to large-scale and useful quantum computers. We have built 5 systems, showing record performance in terms of meaningful circuit depth, and we have several more on the way in a clear engineering path to manufacturability. On the user side, IonQ has installed dedicated quantum computer systems to commercial cloud services, and we are also working directly with strategic customers to help co-design future IonQ systems to the native structure of particular quantum computer algorithms.