Exciton-Polariton Dynamics in Semiconductor Microcavities

Exciton-polaritons are hybrid light–matter quasiparticles arising in semiconductor microcavities when optical modes couple strongly to excitons—bound electron–hole pairs—in embedded quantum wells or two-dimensional materials. In the strong coupling regime, this interaction splits the cavity photon and exciton resonances into lower and upper polariton branches, characterised by unique dispersion relations and allowing ultrafast, coherent dynamics at elevated temperatures. These quasiparticles inherit a light effective mass from photons and interparticle interactions from excitons, enabling the study of nonequilibrium Bose–Einstein condensation, superfluidity and nonlinear optical phenomena within a solid‐state platform. By tailoring microcavity geometry, embedded materials and pump conditions, researchers control polariton lifetimes, coherence lengths and interaction strengths, paving the way for ultralow‐threshold coherent light sources, integrated polaritonic circuits and all‐optical information processing devices.

Research from Nature Portfolio

Recent studies have realised room‐temperature, cascadable all‐optical logic gates by exploiting non‐ground‐state polariton amplification in organic semiconductor microcavities under non‐resonant excitation. The work introduces vibron‐mediated stimulated scattering to achieve inversion (NOT gate) and extends this to a multi‐input NOR gate with picosecond switching times, representing a critical step toward complex polaritonic circuitry. Foundational experiments have demonstrated an all‐optical polariton transistor in inorganic microcavities, where propagating polariton fluids serve as both input and output, yielding high gain and cascadability. This device operates as AND/OR logic by controlling polariton–polariton interactions and condensate flow. Complementing these efforts, an interferometric approach has shown coherent phase modulation in a cavity‐polariton Mach–Zehnder interferometer: strong exciton interactions locally shift the polariton phase, enabling a compact, tunable interferometer whose outputs can be cascaded for quantum‐optical simulations and artificial gauge‐field engineering.

Exciton-Polariton Dynamics in Semiconductor Microcavities publication trend

The graph below shows the total number of articles in exciton-polariton dynamics in semiconductor microcavities across all publications each year (not limited to Nature Index journals).

Technical terms

Exciton: A bound state of an electron and a hole in a semiconductor, behaving as a neutral quasiparticle.

Microcavity: An optical resonator comprised of distributed Bragg reflectors or mirrors that confines photons in a sub‐micrometre thickness.

Strong coupling regime: A condition where the interaction rate between excitons and photons exceeds their respective decay rates, yielding hybrid polariton states.

Polariton condensate: A macroscopic coherent state formed when polaritons collectively occupy the lowest-energy mode under continuous pumping.

Dispersion relation: The dependence of polariton energy on in‐plane momentum, revealing lower and upper polariton branches.

Driven-dissipative: A nonequilibrium scenario in which continuous optical or electrical pumping balances intrinsic losses to sustain a steady polariton population.

References

1. Room temperature, cascadable, all-optical polariton universal gates. Nature Communications (2024).
2. All-optical polariton transistor. Nature Communications (2013).
3. All-optical phase modulation in a cavity-polariton Mach–Zehnder interferometer. Nature Communications (2014).
4. Manipulating nonlinear exciton polaritons in an atomically-thin semiconductor with artificial potential landscapes. Light: Science & Applications (2023).
5. Bogoliubov Excitations Driven by Thermal Lattice Phonons in a Quantum Fluid of Light. Physical Review X (2023).
6. Room temperature long-range coherent exciton polariton condensate flow in lead halide perovskites. Science Advances (2018).