\section{Experimental proposal}




\textbf{\textit{Acknowledgements.}} We thank Jia-Hua Gu, Michael Sch\"utt and Kai Sun for useful discussions and acknowledge
hospitality by the Department of Physics and Astronomy
at Michigan State University (A.L. and E.J.K.)
and by the Department of Physics at University of Michigan
(E.J.K.). This work was financially supported in part by NSF Grants No. DMR-1606517 and ECCS-1560732 (E.J.K. and A.L.). Support for this research at the University of Wisconsin-Madison was provided by the Office of the Vice Chancellor for Research and Graduate Education with funding from the Wisconsin Alumni Research Foundation. Support for this research at Michigan State University was provided by the Institute for Mathematical and Theoretical Physics with funding from the office of the Vice President for Research and Graduate Studies.

