There is no measurement that can directly observe the wave function of a quantum mechanical system, but the wave function is still enormously useful as its (complex) square represents the probability density of the system or elements of the system. But for a confined system, the wave function can be inferred.

Scientists from China have now shown that the wave function’s dependence in space can be determined for a single molecule embedded in a superfluid helium nanodroplet. Their research has been published in the journal Physical Review Letters.