Physics Optical tweezing is a powerful technique for trapping and manipulating particles and can be applied to a broad range of size scales—from single cells and viruses to glass beads several micrometers in diameter. Tweezing can also be used to trap single atoms. However, the interaction between photons in the trapping light beam and the atom generally results in atom jitter. This motion of the atom tends to prevent the atoms from being cooled to the lowest temperatures, where interesting quantum effects can then be probed. Kaufman et al. used an optical trapping beam and a suite of laser pulses to lasso a single rubidium atom and exploited Raman transitions of the atom to cool it to the quantum ground state. Once trapped and cooled to remove all vibrations from the atom, they also show that they could coherently manipulate its quantum spin and motion. The generality and flexibility of the optical tweezing approach may allow more complex systems comprising arrays of overlapping and interacting trapped atoms or molecules to be designed to form quantum simulators (i.e., well-controlled, engineered quantum systems that can be used to model other less-well-understood condensed-matter systems). Phys. Rev. X 2 , 041014 (2012).