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Quantized vortices in mixed 3He-4He drops
1Departament ECM, Facultat de Física, Universitat de Barcelona, E-08028 Barcelona, Spain.
Physical Review Letters
|October 3, 2001
Summary
This study shows that adding helium-3 (3He) to helium-4 (4He) droplets with a vortex line and impurity does not destabilize the system. The impurity remains stable, coated by 4He atoms, even with added 3He.
Area of Science:
- Quantum Fluids
- Low-Temperature Physics
- Computational Physics
Background:
- Quantized vortex lines in superfluid helium droplets are crucial for understanding quantum phenomena.
- Previous work established the stability of a dopant-vortex-(4)He complex below a critical size.
- The effect of mixed helium isotopes on this complex was not fully understood.
Purpose of the Study:
- To investigate the structural stability of mixed (3)He-(4)He droplets containing a quantized vortex line pinned by an impurity.
- To determine how the addition of (3)He affects the stability of the dopant-vortex-(4)He system.
- To calculate the binding energy of the impurity to the vortex line in these mixed droplets.
Main Methods:
- Density Functional Theory (DFT) calculations were employed.
- Simulations involved mixed (3)He(N3)-(4)He(N4) droplets with embedded Xe or HCN impurities.
- The distribution of (3)He atoms and the coating of the impurity by (4)He were analyzed.
Main Results:
- The dopant-vortex-(4)He complex remains energetically stable with the addition of (3)He.
- (3)He atoms distribute along the vortex line and on the surface of the (4)He droplet.
- The impurity is predominantly coated by (4)He atoms, indicating robust structural integrity.
Conclusions:
- Mixed (3)He-(4)He droplets with pinned vortex lines are stable systems.
- The presence of (3)He does not disrupt the core dopant-vortex-(4)He structure.
- The findings provide insights into the behavior of quantum fluids with impurities and mixed isotopes.