Tuning the tricritical point with spin-orbit coupling in polarized fermionic condensates

Area of Science:

• Atomic, Molecular, and Optical Physics
• Condensed Matter Physics
• Quantum Gases

Background:

• Two-component atomic Fermi gases are crucial for studying quantum phenomena.
• Population imbalance and spin-orbit coupling (SOC) are key parameters influencing quantum gas behavior.
• Understanding phase transitions in these systems is essential for quantum simulations.

Purpose of the Study:

• Investigate the effects of Rashba-type spin-orbit coupling (SOC) on the finite-temperature phase diagram of a two-component atomic Fermi gas with population imbalance.
• Explore the competition between SOC and population imbalance.
• Identify new features and phase transitions induced by SOC.

Main Methods:

• Theoretical investigation of a two-component Fermi gas.
• Analysis of the finite-temperature phase diagram.
• Examination of the interplay between spin-orbit coupling and population imbalance.

Main Results:

• The phase diagram exhibits novel features due to the competition between SOC and population imbalance.
• Superfluid state regime expands, while phase separation and normal regimes shrink.
• For strong SOC, the phase separation region vanishes, replaced by the superfluid state.
• The tricritical point shifts towards lower temperatures, higher magnetic fields, and increased polarization with increasing SOC.

Conclusions:

• Spin-orbit coupling significantly alters the phase diagram of imbalanced Fermi gases.
• SOC can stabilize the superfluid phase and suppress phase separation.
• The findings provide insights into controlling quantum states in ultracold atomic gases.