  Trapped-ion quantum information processors store information in atomic ions
maintained in position in free space via electric fields. Quantum logic is
enacted via manipulation of the ions' internal and shared motional quantum
states using optical and microwave signals. While trapped ions show great
promise for quantum-enhanced computation, sensing, and communication, materials
research is needed to design traps that allow for improved performance by means
of integration of system components, including optics and electronics for
ion-qubit control, while minimizing the near-ubiquitous electric-field noise
produced by trap-electrode surfaces. In this review, we consider the materials
requirements for such integrated systems, with a focus on problems that hinder
current progress toward practical quantum computation. We give suggestions for
how materials scientists and trapped-ion technologists can work together to
develop materials-based integration and noise-mitigation strategies to enable
the next generation of trapped-ion quantum computers.
