Phase separations induced by a trapping potential in one-dimensional fermionic systems as a source of core-shell...

Area of Science:

• Condensed Matter Physics
• Quantum Gases
• Atomic Physics

Background:

• Ultracold fermionic gases in optical lattices are crucial for studying novel quantum states.
• Phase separation, particularly core-shell structures, arises from trapping potentials in such systems.
• The emergence of different superfluid phases is influenced by system parameters and trap geometry.

Purpose of the Study:

• To investigate core-shell structures in attractive Fermi gases within optical lattices.
• To analyze the relationship between these structures and the homogeneous system's phase diagram.
• To understand how external and internal system parameters, as well as trap characteristics, affect these structures.

Main Methods:

• Theoretical investigation of attractive Fermi gases in optical lattices.
• Analysis of systems with trapping potentials, including harmonic traps.
• Examination of phase separation phenomena and superfluid state formation.

Main Results:

• Demonstrated the formation of core-shell structures in attractive Fermi gases under specific conditions.
• Identified the dependence of phase types and sequences on spin-imbalance, trap shape, and interaction strength.
• Observed spatial separation of Bardeen-Cooper-Schrieffer (BCS) and Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states in a harmonic trap.
• Found spatial separation between BCS and Bose-Einstein Condensate (BEC) regimes.

Conclusions:

• Core-shell structures in ultracold fermionic gases are sensitive to system and trap parameters.
• The study reveals novel spatial arrangements of superfluid states, including BCS, FFLO, and BEC.
• This work provides insights into the complex phase behavior of interacting Fermi gases in inhomogeneous potentials.