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Entropies and IPR as Markers for a Phase Transition in a Two-Level Model for Atom-Diatomic Molecule Coexistence
Ignacio Baena1, Pedro Pérez-Fernández2,3, Manuela Rodríguez-Gallardo1,3
1Departamento de Física Atómica, Molecular y Nuclear, Facultad de Física, Universidad de Sevilla, Apartado 1065, 41080 Sevilla, Spain.
Entropy (Basel, Switzerland)
|January 21, 2022
Summary
This study explores quantum phase transitions (QPTs) in atomic-molecular systems. New markers like Rényi entropy reveal abrupt changes at the critical point, offering deeper insights into these transitions.
Area of Science:
- Quantum physics
- Condensed matter physics
- Atomic and molecular physics
Background:
- Quantum phase transitions (QPTs) are fundamental phenomena in many-body systems.
- A common model studies the coexistence of atoms and diatomic molecules.
- Traditional QPT markers include ground state energy and particle number expectations.
Purpose of the Study:
- To investigate a simple model exhibiting a second-order ground state phase transition.
- To identify and analyze novel markers for quantum phase transitions.
- To propose inverse participation ratio (IPR) and Rényi entropy as effective QPT indicators.
Main Methods:
- Analysis of a model describing atom-diatomic molecule coexistence.
- Calculation of ground state properties.
- Evaluation of inverse participation ratio (IPR) and Rényi entropy.
Main Results:
- The model exhibits a second-order phase transition from a molecular condensate to an atom-molecule equilibrium.
- Both IPR and Rényi entropy show abrupt changes at the critical point.
- Rényi entropy is highlighted as a particularly sensitive marker for QPT.
Conclusions:
- IPR and Rényi entropy serve as effective markers for quantum phase transitions.
- These novel markers provide complementary insights beyond traditional methods.
- The study deepens the understanding of phase transitions in atomic-molecular systems.
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