In one of the largest quantum simulations ever performed, up to 53 trapped ion qubits have been used to simulate properties of many body magnetic interactions. The qubits are each prepared with individual control, and measured in a single shot with nearly 100% efficiency. This allows the observation of arbitrary correlation functions that cannot be calculated. This restricted quantum computer becomes fully programmable and reconfigurable with straightforward modifications in the control lasers.
- “Observation of a Many-Body Dynamical Phase Transition in a 53-Qubit Quantum Simulator,” J. Zhang, G. Pagano, P. W. Hess, A. Kyprianidis, P. Becker, H. B. Kaplan, A. V. Gorshkov, Z.-X. Gong, and C. Monroe, Nature 551, 601 (2017)
- News Release
Connectivity between qubits in a quantum computer may be as important as clock speed and gate fidelity when it comes time to build large-scale quantum computers. We run several quantum algorithms on two 5-qubit programmable quantum computers: 
In a delicate balance between strong interactions, weak disorder, and a periodic driving force, a collection of trapped ions qubits has been made to pulsate with a period that is relatively insensitive to the drive. This is a time crystal, where the stable pulses emerge and break time symmetry – just like a freezing liquid breaks spatial symmetry and forms a spatial crystal.
In a pair of forward-looking articles, Christopher Monroe, Jungsang Kim, and Kenneth Brown layout the only known method for scaling quantum computers based on demonstrated science and technology. The proposed architecture is based on trapped atomic ion qubits, highlighting the need for “co-design” of applications to the machine and modularity.
It’s just a five-qubit quantum computer, and anything it does is easily simulated on a laptop. However, these trapped ion qubits are fully connected, with entangling gates between all possible pairs. The qubits are dynamically “wired” from the outside with patterns of laser beams, so we can run any algorithm through software without modifying the base hardware. While the individual gate operations are only about 98% pure, it should be possible to exceed the >99.9% purity others have demonstrated with two isolated ions. Most importantly, we have blueprints for scaling this system up to useful dimensions.
Modularity is everywhere, from social networks and transportation hubs to biological function. Modular systems are always necessary for mitigating complexity, especially in computer systems where the latest processors have up to 256 modular cores. 