Shows Kibble-Zurek Scaling in Polariton Condensates with Hundreds of Vortex Realizations

Scientists are increasingly interested in understanding how turbulence emerges in diverse physical systems, and new research sheds light on this phenomenon within a unique ‘fluid of light’. Ivan Krasionov, Anton Putintsev, and Maksim Kolker, alongside Tamsin Cookson, Sergey Alyatkin, and Pavlos G Lagoudakis, all from the Hybrid Photonics Laboratory at the Skolkovo Institute of Science and Technology, have demonstrated single-shot measurements of vortex formation in a room-temperature polariton condensate. Their findings reveal scaling behaviour consistent with both the Kibble-Zurek mechanism and Kolmogorov turbulence, offering a novel platform to investigate spontaneous defect formation and the onset of turbulence in a driven-dissipative system, and providing direct access to quantifying these processes via phase and flow measurements.

The team achieved this breakthrough by employing a novel approach to visualise these quantum phenomena, utilising pulsed excitation and phase-resolved interferometric imaging.

Hundreds of independent realisations were analysed, revealing random vortex-core positions and unbiased circulation, consistent with intrinsically stochastic, unpinned defect formation. This work establishes single-shot access to phase and flow as a direct route to quantifying stochastic defect formation and emerging turbulence in polariton condensates.
The study unveils that the mean vortex number scales with pump power above threshold, exhibiting an exponent consistent with Kibble-Zurek freeze-out in a driven-dissipative condensate. Researchers reconstructed phase maps to obtain single-shot flow fields, subsequently computing the incompressible component and extracting kinetic-energy spectra.

Vortex-containing realisations developed a robust Kolmogorov-like segment with Einc(k) proportional to k^(-5/3) over a finite k range, indicating the onset of turbulent spectral scaling in a fluid of light. This finding is significant as it demonstrates turbulent behaviour within this quantum system. Experiments show that the organic microcavity, fabricated with specific details outlined in the supplementary materials, supports room-temperature condensation when excited with approximately 250 femtosecond pulses at 400nm.

The condensate emission was then split into two detection paths, employing a Mach, Zehnder interferometer to record single-shot interferograms. An off-axis digital holography algorithm was applied to reconstruct both the condensate phase and intensity distributions from these interferograms. The resulting data validated the single-shot reconstruction, confirming the accuracy of the technique.

This research establishes a new method for investigating spontaneous vortex nucleation and emergent turbulence in polariton condensates. By avoiding ensemble averaging, the team was able to statistically analyse individual realisations, providing insights into the dynamics of defect formation. The identification of a Kolmogorov-like spectral segment suggests the emergence of fully developed turbulence in this quantum fluid of light, opening avenues for exploring quantum turbulence and its potential applications in areas such as quantum information processing and novel materials.

Reconstructing condensate phase and flow via single-shot interferometry offers new insights

Scientists employed single-shot interferometry to measure spontaneous vortex nucleation in a room-temperature organic exciton-polariton condensate. The study pioneered a technique using a BODIPY-Br organic microcavity, excited with approximately 250 fs pulses at 400nm focused to a 23μm (FWHM) spot, to achieve room-temperature condensation.

Researchers split the condensate emission into two detection paths, utilizing a Mach, Zehnder interferometer to record single-shot interferograms, with one arm serving as a reference wave to expand and invert the condensate image. An off-axis digital holography algorithm was then applied to reconstruct the condensate phase φ(r, t) and intensity distribution from the interferograms.

This reconstruction enabled the computation of local wavevectors k(r, t) = ∇φ(r, t), revealing the condensate’s flow field, and identified vortex cores with circulation direction indicated by arrow orientation and length proportional to |k|. The team validated the single-shot reconstruction by comparing the intensity-weighted momentum distribution derived from the reconstructed data with simultaneously recorded far-field intensity images.

Experiments involved analysing hundreds of independent realizations to determine vortex-core positions and circulation, finding them unbiased and consistent with unpinned defect formation. By varying pump power above threshold, the research tested Kibble-Zurek scaling of the mean vortex number, establishing a correlation between excitation and vortex density.

Single-shot flow fields were extracted to obtain incompressible kinetic-energy spectra, revealing a Kolmogorov-like segment with Einc(k) proportional to k^(-5/3) over a finite k range, indicating the onset of turbulent spectral scaling in the fluid of light. This innovative approach provides direct access to phase and flow, quantifying stochastic defect formation and emergent turbulence in polariton condensates.

Spontaneous Vortex Nucleation Reveals Turbulent Scaling in a Room-Temperature Bose-Einstein Condensate

Scientists achieved single-shot interferometric measurements of spontaneous vortex nucleation in a room-temperature organic exciton-polariton condensate. From hundreds of independent realizations, the team found random vortex-core positions and unbiased circulation, consistent with intrinsically stochastic, unpinned defect formation.

The mean vortex number scales with pump power above threshold with an exponent consistent with Kibble-Zurek freeze-out in a driven-dissipative condensate. Using reconstructed phase maps, researchers obtained single-shot flow fields and computed the incompressible component, subsequently extracting kinetic-energy spectra.

Vortex-containing realizations developed a robust Kolmogorov-like segment with Einc(k) proportional to k^(-5/3) over a finite k range, indicating the onset of turbulent spectral scaling in a fluid of light. These results establish single-shot access to phase and flow as a direct route to quantifying stochastic defect formation and emerging turbulence in polariton condensates.

Experiments utilized a BODIPY-Br organic microcavity, fabricating a system supporting room-temperature condensation under ultrafast optical pumping. The condensate was excited with approximately 250 femtosecond pulses at 400nm, focused to a 23μm full width at half maximum spot. Single-shot interferograms were recorded using a Mach, Zehnder interferometer, employing an off-axis digital holography algorithm to reconstruct the condensate phase.

Reconstructed real-space phase profiles revealed local wavevector fields, with arrow lengths proportional to the magnitude of k. Blue and red arrows denoted vortex cores with counterclockwise and clockwise circulation respectively. Far-field intensity distributions were reconstructed from the condensate density profiles, matching experimentally measured far-field intensity images.

The mean vortex number was found to scale with pump power, demonstrating consistency with Kibble-Zurek freeze-out predictions for driven-dissipative condensates. Measurements confirm the emergence of a Kolmogorov-like spectral segment, signifying turbulent spectral scaling within the quantum fluid of light.

Turbulence and the Kibble-Zurek mechanism in a room-temperature exciton-polariton condensate offer new insights into non-equilibrium dynamics

Scientists have demonstrated single-shot interferometric imaging of vortex nucleation within a room-temperature organic exciton-polariton condensate. Hundreds of independent realisations were analysed, revealing random vortex core positions and unbiased circulation, indicative of stochastic and unpinned defect formation.

The average number of vortices observed scaled with pump power above the threshold, exhibiting an exponent consistent with the Kibble-Zurek mechanism for driven-dissipative condensates. Reconstructed phase maps facilitated the acquisition of single-shot flow fields and incompressible kinetic-energy spectra.

Vortex-containing realisations displayed a Kolmogorov-like spectral segment, with Einc(k) proportional to k^(-5/3) over a limited range of k values, suggesting the emergence of turbulent spectral scaling in this quantum fluid of light. While acknowledging limitations imposed by finite system size and a maximum vortex number of three, the authors highlight that the observed scaling provides a foundation for investigating the development of turbulence with increasing vortex density and clustering. Future work could explore the behaviour of these condensates with higher vortex numbers to fully establish a flux-supported inertial range and further characterise the transition to fully developed turbulence.