Tunable Magnetic Alignment between Trapped Exciton-Polariton Condensates

Area of Science:

• Quantum optics
• Condensed matter physics
• Semiconductor physics

Background:

• Exciton-polaritons are quasiparticles formed from the coupling of excitons and photons in semiconductor microcavities.
• Spontaneous spin polarization in polariton condensates is a key phenomenon for quantum information processing.
• Controlling interactions between multiple condensates is crucial for building complex quantum systems.

Purpose of the Study:

• To investigate tunable spin correlations between neighboring trapped exciton-polariton condensates.
• To demonstrate real-time control over the magnetic ordering (antiferromagnetic to ferromagnetic) of condensate pairs.
• To achieve fast optical switching of coupled polariton condensates.

Main Methods:

• Utilizing trapped exciton-polariton condensates in semiconductor microcavities.
• Dynamically tuning the coupling barrier between condensates by controlling the pump light pattern.
• Employing resonant optical triggering of a single condensate to induce switching in the pair.

Main Results:

• Observed spontaneous spin polarization and tunable spin correlations between two adjacent condensates.
• Demonstrated a crossover from antiferromagnetic to ferromagnetic coupling by reducing the inter-condensate barrier.
• Achieved fast, resonant optical switching of both condensates by manipulating a single condensate.

Conclusions:

• The observed phenomena are explained by the interplay of spin bifurcations and spin-preserving Josephson coupling.
• The findings pave the way for creating polariton Bose-Hubbard ladders.
• This work offers a new platform for exploring quantum correlations and developing novel optical switching devices.