Measurements of spatial correlations in quantum gases using ultralong-range strontium Rydberg molecules

The photoexcitation of ultralong-range Rydberg molecules is demonstrated as a probe of spatial correlations in a quantum gas on previously inaccessible length scales of 1400-3200 a(0). Measurements using cold (similar to 1 mu K) (fermionic) Sr-87 and (bosonic) Sr-84 reveal the effects of quantum statistics on the pair correlation function g((2))(R).