The phase-separation mechanism of a binary mixture in a ring trimer.

Area of Science:

• Quantum physics
• Condensed matter physics
• Quantum information theory

Background:

• Understanding macroscopic quantum phenomena in multi-component systems is crucial.
• Phase separation and mixing dynamics are fundamental in many-body systems.
• Quantum entanglement plays a key role in characterizing complex quantum states.

Purpose of the Study:

• To investigate the macroscopic ground-state configurations of a binary mixture in a three-well potential.
• To explore the relationship between inter- and intra-species interactions and system behavior.
• To identify quantum signatures of phase transitions using entanglement entropy.

Main Methods:

• Theoretical modeling of a binary mixture in a three-well potential with periodic boundary conditions.
• Analysis of ground-state configurations and their dependence on interaction ratios.
• Examination of quantum state properties, including delocalization and Schrödinger cat-like structures.
• Spectroscopic analysis of the energy spectrum to identify critical points.
• Calculation of Entanglement Entropy to detect phase transitions.

Main Results:

• Three distinct macroscopic ground-state configurations emerge, varying in mixing degree.
• Quantum states exhibit either delocalization or Schrödinger cat-like structures.
• A two-step phase separation is observed, influenced by quantum tunneling.
• The energy spectrum shows characteristic collapses and rearrangements at two critical points.
• Entanglement Entropy exhibits singularities at critical points, signaling a double mixing-demixing transition.

Conclusions:

• The study reveals novel ground-state configurations in binary mixtures driven by interaction tuning.
• Entanglement Entropy serves as a robust indicator for complex phase transitions in quantum systems.
• The findings provide insights into demixing mechanisms and open avenues for studying quantum systems in intricate lattice geometries.