Simulating Quantum Magnetism with Correlated Non-Neutral Ion Plasmas | NIST

B. M. Jelenković, T. B. Mitchell, J. J. Bollinger +4 more

J. J. Bollinger, J. Britton, Brian C. Sawyer

By employing forces that depend on the internal electronic state (or spin) of an atomic ion, the Coulomb potential energy of a strongly coupled array of ions can be modified in a spin-dependent way to mimic effective quantum spin Hamiltonians. Both ferromagnetic and anti-ferromagnetic interactions can be implemented. We use simple models to explain how the effective spin interactions are engineered with trapped-ion crystals. We summarize the type of effective spin interactions that can be readily generated, and discuss an experimental implementation using single-plane ion crystals in a Penning trap.

Ian B. Spielman

Kevin Gilmore, Justin Bohnet, J. E. Jordan +4 more

T X Chen, R H Lu, L Guo +1 more

Abstract The correlation of ultracold neutral plasmas extracted from the pair correlation function is presented in detail. To get its spatial distribution and time evolution, a large scale simulation using a full molecular-dynamics method with open boundary condition is performed, and the expansion of an ultracold plasma is simulated. We demonstrate that the coupling strength extracted from pair correlation is a good measure for the correlation in ultracold plasma except at the very early stage. The ion–ion pair correlation arises at the timescale of ω pi − 1 . And results imply that there is a strong coupling area at the outer plasma during the expansion.

Grant M. Gorman, M. K. Warrens, S. J. Bradshaw +1 more

We demonstrate magnetic confinement of an ultracold neutral plasma (UCNP) created at the null of a biconic cusp, or quadrupole magnetic field. Initially, the UCNP expands due to electron thermal pressure. As the plasma encounters stronger fields, expansion slows and the density distribution molds to the field. UCNP electrons are strongly magnetized over most of the plasma, while ion magnetization is only significant at the boundaries. Observations suggest that electrons and ions are predominantly trapped by magnetic mirroring and ambipolar electric fields, respectively. Confinement times approach 0.5 ms, while unmagnetized plasmas dissipate on a timescale of a few tens of microseconds.