Single-Spin Addressing in an Atomic Mott Insulator

Understand

Ultracold atoms in optical lattices are a versatile tool to investigate fundamental properties of quantum many body systems.

• In particular, the high degree of control of experimental parameters has allowed the study of many interesting phenomena such as quantum phase transitions and quantum spin dynamics.
• Here we demonstrate how such control can be extended down to the most fundamental level of a single spin at a specific site of an optical lattice.
• Using a tightly focussed laser beam together with a microwave field, we were able to flip the spin of individual atoms in a Mott insulator with sub-diffraction-limited resolution, well below the lattice spacing.