Competitive localization of vortex lines and interacting bosons.

Area of Science:

• Condensed matter physics
• Quantum mechanics

Background:

• Vortex lines and bosons exhibit complex behaviors when interacting with defects.
• Understanding particle localization and delocalization is crucial for quantum systems.

Purpose of the Study:

• To develop a theory for the localization of three-dimensional (3D) vortex lines and two-dimensional (2D) bosons.
• To investigate a novel delocalization transition in systems with competing interactions for a single defect.

Main Methods:

• A necklace model approach was employed for analyzing two-vortex systems.
• Theoretical calculations were performed to determine transition points and order.

Main Results:

• A new exchange-delocalization transition was identified between two distinct single-bound particle states.
• This transition occurs with weak vortex-vortex repulsion or binding energy (high temperature).
• The transition point and order were calculated, with a proposed generalization for arbitrary vortex numbers.

Conclusions:

• The study reveals a new mechanism for particle delocalization and exchange in quantum systems near defects.
• The findings provide insights into the behavior of interacting vortices and bosons in confined potentials.