In collaboration with Elena Jordan, Kevin Gilmore, Matt Affolter, Arghavan Safavi-Naini, Robert Lewis-Swan, Wenchao Ge, Murray Holland, and Ana Maria Rey
This talk will discuss our efforts to improve the control of large ion crystals in Penning traps and employ these crystals for quantum simulation and sensing. Penning traps utilize static electric and magnetic fields for confinement, enabling the formation of large two- and three-dimensional ion crystals. Our current work focuses on single-plane crystals of several hundred 9Be+ ions. Through electromagnetically induced transparency (EIT) we have recently ground-state cooled the hundreds of drumhead modes in this system.
Like many quantum platforms, the interactions between ion qubits is mediated by bosons, in this case the phonons of the ion crystal. We use optical dipole forces to couple the ion qubit (or spin) with the motional degree of freedom. When the spins are coupled to a single motional mode (typically the center-of-mass mode), this system is described by the iconic Dicke model. Long-range Ising interactions and single-axis twisting are produced through this spin-motion coupling. To benchmark dynamics, we measure out-of-time-order correlations (OTOCs) that quantify the build-up of correlations and the spread of quantum information. To enhance the spin-spin interactions we propose to parametrically drive the ion crystal phonons.
We also employ spin-dependent optical dipole forces to sense center-of-mass motion that is small compared to the ground state zero-point fluctuations. This enables the detection of weak electric fields and may provide an opportunity to place limits on dark matter couplings due to particles such as axions and hidden photons that couple to ordinary matter through weak electric fields.