Real-space collapse of a polariton condensate

Abstract

Microcavity polaritons are two-dimensional bosonic fluids with strong nonlinearities, composed of coupled photonic and electronic excitations. In their condensed form, they display quantum hydrodynamic features similar to atomic Bose–Einstein condensates, such as long-range coherence, superfluidity and quantized vorticity. Here we report the unique phenomenology that is observed when a pulse of light impacts the polariton vacuum: the fluid which is suddenly created does not splash but instead coheres into a very bright spot. The real-space collapse into a sharp peak is at odd with the repulsive interactions of polaritons and their positive mass, suggesting that an unconventional mechanism is at play. Our modelling devises a possible explanation in the self-trapping due to a local heating of the crystal lattice, that can be described as a collective polaron formed by a polariton condensate. These observations hint at the polariton fluid dynamics in conditions of extreme intensities and ultrafast times.

Stabilization of ring dark solitons in Bose-Einstein condensates

“…Our scope is to provide a systematic understanding of the RDS instability modes and how to suppress them, so as to potentially enable its experimental realization. Similar considerations in the context of exciton-polariton condensates (where a larger range of tunable parameters exists due to the open nature of the system and the presence of gain and loss) have led both to the theoretical analysis [50] and to the experimental observation [51] of stable RDSs. Following the motivation of the earlier work of Ref.…”

Pulse, polarization and topology shaping of polariton fluids

“…In the specific, two-dimensional microcavities embedding inorganic quantum wells (QWs) 34 have attracted attention for their ability to reach the regime of Bose-Einstein condensation 35 and superfluidity, 11,36 with a plethora of collective wavefunction phenomena hydrodynamics including coherence, quantized vorticity, strong nonlinearities and real-space pattern formation. 4,5,8,37,38 On the application side, the most intriguing perspectives involve schemes and demonstrations for new polariton lasers 39,40 and all-optical transistors and logical operations. 41 Pioneering attempts to observe the Rabi oscillations at the core of the polariton physics, encountered intrisic difficulties represented, e.g., by their sub-ps time range and reported very few oscillations with orders of magnitude visibility loss each cycle.…”

“…The realization of exciton polariton condensates in semiconductor microcavities 2,3 has paved the way for a prolific series of studies into quantum hydrodynamics in two-dimensional systems. [4][5][6][7][8][9][10][11][12] Microcavity polaritons are intriguing systems for the study of topological excitations in nonequilibrium interacting superfluids, also thanks to rich spinorial patterns and polarization splitting terms leading to typical spin-orbit coupling.…”

Catastrophes in non-equilibrium many-particle wave functions: universality and critical scaling

“…On the theoretical side, caustics have been predicted to occur in atomic diffraction from standing waves of light [39], in atom clouds in pulsed optical lattices [40,41], in the dynamics of particles with longrange interactions [42], in the expansion dynamics of Bose gases released from one-and two-dimensional traps [43], and they can also produce characteristic features in the long-time (but non-thermal) probability distribution following quenches in optical lattices and Josephson junctions [44,45]. Furthermore, although not identified as such by their authors, caustics can be seen in figures in papers on the dynamics of BECs encountering a supersonic obstacle [46], on the collapse and subsequent spreading of a BEC of polaritons pulsed by a laser [47] and in quantum random walks by interacting bosons in an optical lattice [48]. The properties of caustics depend on the scale at which they are viewed.…”