arXiv subjects

I. Carraro-Haddad

Publications and source records attributed to I. Carraro-Haddad.

3 recordsLinked to original sources

arXiv2026

Synchronization in coherently and dissipatively coupled spinor polariton time crystals

The spinor degree of freedom associated to exciton-polariton condensates can spontaneously self-oscillate breaking time translation symmetry, thus showing a continuous time-crystal (CTC) behavior. An open question in such driven-dissipative and non-linear quantum open systems is what happens when CTCs are brought together to interact. Here we experimentally study polariton condensates in coupled traps, evidencing mutual induction and synchronization of the pseudospin temporal GHz dynamics in the CTC phase. The individual and relative orientation of the (limit cycle) precessing pseudospins can be tuned by the optical excitation power, displaying both ferro and anti-ferro dynamical configurations. We theoretically show that the exciton reservoir, and both the coherent and long-range dissipative inter-trap coupling, play important roles in the CTC dynamics. The investigation of time-broken symmetry is thus extended here to more complex non-hermitian systems opening the path to study self-sustained collective dynamics in lattices of non-linear quantum condensates.

cond-mat.other↗

arXiv2026

Coherent Control of a Polariton Continuous Time Crystal

Spontaneous breaking of time-translation symmetry and the emergence of self-sustained oscillations in quantum driven-dissipative systems is the hallmark of continuous time crystals (CTCs). An outstanding challenge is to achieve precise, coherent control of such dynamical phases, whose complex nonlinear dynamics makes them inherently difficult to manipulate. Here, we experimentally demonstrate coherent control of a solid-state CTC realized in a non-resonantly excited spin-polarized exciton-polariton condensate in a Ga(Al)As microcavity. We exploit two complementary control channels: an additional weak control laser and the optomechanical interaction with confined GHz phonons. By tuning the control laser energy and power, we stabilize distinct dynamical regimes, including frequency pushing, injection locking with continuous tuning of the limit-cycle frequency, and full suppression of the autonomous dynamics via phase locking. Under appropriate detuning conditions, the control excitation generates coherent mechanical self-oscillation through the polariton--phonon deformation-potential interaction, evidenced by spectral sidebands. The resulting dynamical back-action provides a phonon-mediated locking channel that fixes the frequency of the CTC. Together, the two channels dramatically enhance the temporal coherence of the GHz limit-cycle dynamics, as established through linewidth narrowing and time-resolved first-order correlation measurements $\gone(τ)$. Our work establishes a way to harness the unique aspects of CTCs for practical applications in the GHz-range.

physics.optics↗

arXiv2024

Theory of Optomechanical Locking in Driven-Dissipative Coupled Polariton Condensates

The ubiquitous phenomenon of synchronization is inherently characteristic of dynamical dissipative non-linear systems. In particular, synchronization has been theoretically and experimentally demonstrated for exciton-polariton condensates with time-independent coupling. Unlike that case, we theoretically investigate the effects of a fixed mechanical harmonic driving, i.e., a coherent phonon population, that induces time modulation in the coupling of two coupled condensates. Our model applies both to electrically generated modulation, through coherent bulk acoustic waves, and to self-induced optomechanical vibrations. We consider linear as well as quadratic phonon-displacement-induced modulations of the polariton coupling. Peculiar asynchronously locked phases are found and analyzed in the context of synchronization and Josephson-type oscillations phenomena that appear in the non-driven case. Notably, Arnold tongues corresponding to the asynchronously locked phases emerge at condensate detunings that correspond to integer numbers of the mechanical frequency and also to rational fractions of it. Unlocked quasiperiodic and chaotic regimes can also be reached. In particular, the phonon-induced fractional locking frequencies arrange in a Farey sequence that produces a devil's staircase of the steady-state dressed detuning between the condensates. Importantly, both polariton-polariton and reservoir-polariton interactions facilitate the realization of coherent phonon-induced asynchronously locked phases. The relation to recent experiments on optomechanically driven condensates in arrays of polariton traps is discussed.

physics.optics↗