The quest to build a powerful quantum computer is one of the great challenges of 21st century physics. And although the hurdles are significant, physicists are chasing them down, one by one.
They’ve gradually learned how to control quantum particles with the precision necessary to run quantum algorithms on a small scale with just a few qubits.
Quantum computers can solve certain problems more efficiently than any possible conventional computer. Small quantum algorithms have been demonstrated in multiple quantum computing platforms, many specifically tailored in hardware to implement a particular algorithm or execute a limited number of computational paths. Here, we demonstrate a trapped-ion quantum computer module that can be programmed in software to implement arbitrary quantum algorithms by executing any sequence of universal quantum logic gates. We compile algorithms into a fully-connected set of gate operations native to the hardware. Reconfiguring these gate sequences provides the flexibility to implement a variety of algorithms without altering the hardware. As examples, we implement the Deutsch- Jozsa (DJ), Bernstein-Vazirani (BV), and quantum Fourier transform (QFT) algorithms on five trapped-ion qubits. This small quantum computer can be scaled to larger numbers of qubits within a single module, and can be further expanded by connecting many modules through ion shuttling or photonic quantum channels.