There is a recent publication in PRL (Feb. 2014) by Schmidt et al., which says that there are vortices associated with the wave function of a single electron. Their abstract is as follows: "We present measurements and calculations of the momentum distribution of electrons emitted during the ion-atom collision ... which show rich structures for ion scattering angles above 2 mrad arising dominantly from two-electron states. Our calculations reveal that minima in the measured distributions are zeros in the electronic probability density resulting from vortices in the electronic current." (ref. http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.083201, or see: http://arxiv-web3.library.cornell.edu/pdf/1402.6853.pdf).
This paper reminds me to Kobayashi and Shimbori's paper (2001) suggesting that there is vortex solution of Schrodinger equation. (ref. http://arxiv.org/pdf/cond-mat/0103209.pdf).
Can vortices be associated with the wave function of electron?