Acknowledgements

This material is based upon work supported by the Department of Energy under Grant Numbers 64377, 56840, 80780, 561096, DEFG02-03ER41281, DEFG02-91ER40677, DE-SC0009932, DOE2016-02567 and DOE2016-05127. This material is also based on work supported by the National Science Foundation under Grant Numbers PHY03-49179, PHY04-26272, and PHY10-56987. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Department of Energy or National Science Foundation.