Quantum Computing and Quantum Simulation with Group-II Atoms

Recent experimental progress in controlling neutral group-II atoms for optical clocks, and in the production of degenerate gases with group-II atoms has given rise to novel opportunities to address challenges in quantum computing and quantum simulation. In these systems, it is possible to encode qubits in nuclear spin states, which are decoupled from the electronic state in the $^1$S$_0$ ground state and the long-lived $^3$P$_0$ metastable state on the clock transition. This leads to quantum computing scenarios where qubits are stored in long lived nuclear spin states, while electronic states can be accessed independently, for cooling of the atoms, as well as manipulation and readout of the qubits. The high nuclear spin in some fermionic isotopes also offers opportunities for the encoding of multiple qubits on a single atom, as well as providing an opportunity for studying many-body physics in systems with a high spin symmetry. Here we review recent experimental and theoretical progress in these areas, and summarise the advantages and challenges for quantum computing and quantum simulation with group-II atoms.Comment: 11 pages, 7 figures, review for special issue of "Quantum Information Processing" on "Quantum Information with Neutral Particles

Occupational exposure to trichloroethylene and risk of non-Hodgkin lymphoma and its major subtypes: a pooled InterLymph analysis

Objectives: We evaluated the association between occupational exposure to trichloroethylene (TCE) and risk of non-Hodgkin lymphoma (NHL) in a pooled analysis of four international case-control studies. Methods: Overall, the pooled study population included 3788 NHL cases and 4279 controls. Risk of NHL and its major subtypes associated with TCE exposure was calculated with unconditional logistic regression and polytomous regression analysis, adjusting by age, gender and study. Results: Risk of follicular lymphoma (FL), but not NHL overall or other subtypes, increased by probability (p=0.02) and intensity level ( p=0.04), and with the combined analysis of four exposure metrics assumed as independent ( p=0.004). After restricting the analysis to the most likely exposed study subjects, risk of NHL overall, FL and chronic lymphocytic leukaemia (CLL) were elevated and increased by duration of exposure (p=0.009, p=0.04 and p=0.01, respectively) and with the combined analysis of duration, frequency and intensity of exposure (p=0.004, p=0.015 and p=0.005, respectively). Although based on small numbers of exposed, risk of all the major NHL subtypes, namely diffuse large B-cell lymphoma, FL and CLL, showed increases in risk ranging 2-3.2-fold in the highest category of exposure intensity. No significant heterogeneity in risk was detected by major NHL subtypes or by study. Conclusions: Our pooled analysis apparently supports the hypothesis of an increase in risk of specific NHL subtypes associated with occupational exposure to TCE