Spin-Orbit Coupling and Spin Textures in Optical Superlattices.

Area of Science:

• Atomic physics
• Quantum mechanics
• Condensed matter physics

Background:

• Spin-orbit coupling is crucial for many quantum phenomena.
• Existing methods often require specific atomic properties or near-resonant light.
• Controlling interactions in ultracold atom systems is a key challenge.

Purpose of the Study:

• To propose and demonstrate a novel, versatile approach for realizing spin-orbit coupling in ultracold atoms.
• To utilize orbital levels in a double-well potential as pseudospin states for this purpose.
• To investigate the resulting behavior of Bose-Einstein condensates.

Main Methods:

• Employing orbital levels within a double-well potential to define pseudospin states.
• Utilizing two-photon Raman transitions between the wells to induce spin-orbit coupling.
• Shaping the double-well potential to tune atomic interactions.

Main Results:

• Successfully demonstrated a new scheme for inducing spin-orbit coupling.
• The method is independent of specific atomic properties and does not require near-resonant light.
• A pseudospinor Bose-Einstein condensate spontaneously developed an antiferromagnetic pseudospin texture.
• This texture spontaneously broke lattice symmetry, exhibiting supersolid-like behavior.

Conclusions:

• The proposed method offers a flexible and atom-independent way to achieve spin-orbit coupling.
• The observed spontaneous antiferromagnetic texture and symmetry breaking in Bose-Einstein condensates are significant findings.
• This work opens new avenues for exploring quantum many-body physics with ultracold atoms.