Pinning of quantized vortices in helium drops by dopant atoms and molecules
Using a density functional method, we investigate the properties of liquid 4He droplets doped with atoms (Ne and Xe) and molecules ( SF6 and hydrogen cyanide). We consider the case of droplets having a quantized vortex pinned to the dopant. A liquid-drop formula is proposed that accurately describes the total energy of the complex and allows one to extrapolate the density functional results to large N. For a given impurity, we find that the formation of a dopant+vortex+(4)He(N) complex is energetically favored below a critical size N(cr). Our results support the possibility to observe quantized vortices in helium droplets by means of spectroscopic techniques.
Dalfovo
F
Dipartimento di Matematica e Fisica, Universita Cattolica, Via Musei 41, I-25121 Brescia, Italy and and Istituto Nazionale per la Fisica della Materia, Unita di Trento, I-38050 Povo, Italy.
Mayol
R
Pi
M
Barranco
M