Gap solitons in a spin-orbit-coupled Bose-Einstein condensate.

Area of Science:

• Quantum physics
• Condensed matter physics
• Atomic physics

Background:

• Bose-Einstein condensates (BECs) are quantum states of matter.
• Spin-orbit coupling and periodic potentials are crucial for novel quantum phenomena.
• Gap solitons are localized states in periodic potentials.

Purpose of the Study:

• To investigate stable gap solitons in spin-orbit-coupled BECs.
• To classify these solitons based on their symmetries.
• To understand the role of Zeeman fields in soliton formation.

Main Methods:

• Theoretical modeling of spin-orbit-coupled BECs.
• Analysis of solitons in spatially periodic Zeeman fields.
• Classification of solitons by parity (P), time (T), and spin (C) symmetries.

Main Results:

• A diversity of stable gap solitons was observed.
• Solitons were classified by P, T, and C symmetries.
• Conventional gap and gap-stripe solitons were identified.
• Solitons with identical types but different symmetries were found at distinct locations.
• PT and CPT symmetric solitons exhibited antiferromagnetic structures with distinct magnetizations.

Conclusions:

• Symmetry plays a key role in classifying gap solitons in spin-orbit-coupled BECs.
• The spatial Zeeman field is critical for generating diverse soliton types.
• The findings provide insights into the fundamental properties of matter waves in complex potentials.