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Exciton Polaritons in a Two-Dimensional Lieb Lattice with Spin-Orbit Coupling.
C E Whittaker1, E Cancellieri1,2, P M Walker1
1Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom.
Physical Review Letters
|March 17, 2018
Summary
Researchers explored exciton polaritons in a Lieb lattice, achieving bosonic condensation in flat bands. This led to unique emission patterns due to spin-orbit coupling, showing potential for emulating complex quantum systems.
Area of Science:
- Quantum optics and condensed matter physics.
- Investigating light-matter interactions in engineered photonic structures.
Background:
- Exciton polaritons are quasiparticles formed from the strong coupling of excitons and photons.
- Flat bands in lattices can host novel quantum phenomena due to reduced kinetic energy.
- Photonic spin-orbit coupling links particle spin to its momentum, influencing light behavior.
Purpose of the Study:
- To study exciton polaritons in a two-dimensional Lieb lattice.
- To investigate the formation of bosonic condensates in flat energy bands.
- To explore the role of spin-orbit coupling and orbital symmetry in condensate properties.
Main Methods:
- Fabrication of a two-dimensional Lieb lattice using micropillars.
- High-power optical excitation to induce bosonic condensation.
- Analysis of emission patterns to probe condensate properties and spin textures.
Main Results:
- Observed bosonic condensation within two flat energy bands derived from S and P_{x,y} photonic orbitals.
- Demonstrated emission patterns with pseudospin texture in flat band condensates.
- Correlated emission patterns with the symmetry of orbital wave functions and spin-orbit coupling.
Conclusions:
- Polariton lattices are promising platforms for emulating flat band Hamiltonians.
- The system exhibits controllable quantum phenomena including spin-orbit coupling and orbital degrees of freedom.
- Potential for studying interacting quantum many-body physics in a tunable system.
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