Britton, Joseph W.

Tuesday Nov 12, 2013
Time: 16:00
Place: ETH Science City, HPF G 6
Host: Jonathan Home

Engineered spin-motion and spin-spin interactions on a 2D array of trapped ions

Joseph W. Britton
National Institute of Standards and Technology, Boulder, Colorado, USA

Ising interactions are one paradigm used to model quantum magnetism in condensed matter systems. Depending on the details of the interaction, ground states with very different order emerge (e.g. paramagnetic, ferromagnetic or antiferromagnetic). Of particular interest are systems where the underlying lattice structure can frustrate long-range ordering resulting in spin-liquid behavior.  At NIST Boulder we confine two-dimensional 9Be+ crystals consisting of hundreds of ions in a Penning trap. The valence electron of each ion behaves as an ideal spin-1/2 particle and the ions naturally form a two-dimensional triangular lattice. The Ising interaction is generated by a spin-dependent optical dipole force. We have exploited this spin-dependent force for spectroscopy and thermometry of the normal modes of the trapped ion array; a detailed understanding of the modes is important because they mediate the spin-spin interactions. We have also demonstrated a variable-range anti-ferromagnetic Ising interaction. The high spin-count, good quantum control of Penning-trapped ions brings within reach simulation of computationally intractable problems in quantum magnetism.