Abstract
The development of small-scale sensors and actuators enables the construction of smart matter in which physical properties of materials are controlled in a distributed manner. In this paper, we describe how quantum computers could provide an additional capability, programmable control over some quantum behaviors of such materials. This emphasizes the need for spatial coherence, in contrast to the more commonly discussed issue of temporal coherence for quantum computing. We also discuss some possible applications and engineering issues involved in exploiting this possibility.