Quantum Control with Ultracold Atoms

Ultracold atoms have long been considered as a platform for quantum information processing. Of critical importance is the ability to coherently control both internal degrees of freedom such as spin and also interactions between atoms that depend on ``external'' motional degrees of freedom. In this talk I will review a variety of advances, including the ability to perform qudit operations such as state preparation and unitary gates, quantum-state reconstruction via continuous measurement, and cooling of atomic motion without decohering spin qubits. Two different platforms will be presented -- alkali atoms transported in a lattice with microwave-induced spin-flips, and alkaline-earth atoms in which quantum information is stored in nuclear spins. Microwave-induced spin flips provide a robust mechanism for inducing cold collisions between atoms that can form the basis of a quantum logic gate. As an alternative, cold alkaline-earth atoms are attractive since the ground state is a closed shell, with zero electron angular momentum. The nuclear spin is thus decoupled from the system and can acts as robust decoherence-free qubit.