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Updated: Jun 19, 2026
13:39
Optical Trapping of Nanoparticles
Published on: January 15, 2013
Pattern switching and polarizability for colloids in optical-trap arrays.
C Reichhardt1, C J Olson Reichhardt
1Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Summary
Colloidal crystals interacting with substrates and rotating fields can rapidly switch patterns and orientation. This behavior, including martensiticlike symmetry switching, offers potential for new photonic band-gap devices.
Area of Science:
- Condensed matter physics
- Soft matter physics
- Materials science
Background:
- Colloidal crystals are model systems for studying phase transitions and collective behavior.
- Interactions with periodic substrates and external fields can induce novel dynamic phenomena.
Purpose of the Study:
- To investigate the dynamic behavior of colloidal molecular crystal states under combined substrate and rotating field driving.
- To explore pattern switching, symmetry changes, and emergent polarized states in driven colloidal systems.
Main Methods:
- Simulations or experiments involving colloidal crystals confined to a periodic optical-trap array.
- Application of a rotating external field to drive the system.
- Analysis of crystal orientation, symmetry, and emergent director fields.
Main Results:
- Observed rapid pattern switching and orientation changes in colloidal crystals.
- Demonstrated martensiticlike symmetry switching under specific conditions.
- Created polarized states with smoothly rotating director fields, analogous to liquid crystals.
Conclusions:
- Driven colloidal crystals exhibit rich dynamic responses, including rapid pattern switching and symmetry changes.
- The observed phenomena, particularly polarized states, are reminiscent of liquid crystal behavior.
- These findings suggest potential applications in photonic band-gap materials and other driven condensed matter systems.
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