Seth Lovett | Searcharxiv

arXiv2025

Flat-band compactons in a two-dimensional driven-dissipative Lieb lattice

We experimentally study the effect of inter-particle interactions on the flat-band states of a two-dimensional Lieb lattice with drive and dissipation. Exploiting the giant nonlinear interactions of exciton polaritons we observe compactly localised solitons (compactons) embedded within the continuum of propagating state bands -- a form of nonlinear bound state in the continuum (BIC). The driven-dissipative nature of the system leads to a sudden self-localisation into the compacton state above a threshold power. The experimental results agree well with numerical simulations. These results have implications for the physics of interacting quantum particles in flat-band systems and for generation of quantum-correlated light and spatially multiplexed coherent information transport.

cond-mat.other↗

arXiv2023

Observation of Zitterbewegung in photonic microcavities

We present and experimentally study the effects of the photonic spin-orbit coupling on real space propagetion of polariton wavepackets in planar semiconductor microcavities and polaritonic analogs of graphene. In particular, we demonstrate the appearance of an analog Zitterbewegung effect, a term which translates as 'trembling motion' in english, which was originally proposed for relativistic Dirac electrons and consists of the oscillations of the center of mass of a wavepacket in the direction perpendicular to its propagation. For a planar microcavity we observe regular Zitterbewegung oscillations whose amplitude and period depend on the wavevector of the polaritons. We then extend these results to a honeycomb lattice of coupled microcavity resonators. Compared to the planar cavity such lattices are inherently more tuneable and versatile, allowing simulation of the Hamilitonians of a wide range of important physical systems. We observe an oscillation pattern related to the presence of the spin-split Dirac cones in the dispersion. In both cases the experimentally observed oscillations are in good agreement with theoretical modelling and independently measured bandstructure parameters, providing strong evidence for the observation of Zitterbewegung.

physics.optics↗