Synchronization of spin-driven limit cycle oscillators optically levitated in vacuum

0579366 - ÚPT 2024 RIV US eng J - Journal Article
Brzobohatý, Oto - Duchaň, Martin - Jákl, Petr - Ježek, Jan - Šiler, Martin - Zemánek, Pavel - Simpson, Stephen Hugh
Synchronization of spin-driven limit cycle oscillators optically levitated in vacuum.
Nature Communications. Roč. 14, č. 1 (2023), č. článku 5441. E-ISSN 2041-1723
R&D Projects: GA ČR(CZ) GF21-19245K; GA MŠMT(CZ) EF16_026/0008460
Grant - others:AV ČR(CZ) AP2002
Program: Akademická prémie - Praemium Academiae
Institutional support: RVO:68081731
Keywords : optical levitation * optical binding * synchronization
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 16.6, year: 2022
Method of publishing: Open access
https://www.nature.com/articles/s41467-023-41129-5

We explore, experimentally and theoretically, the emergence of coherent coupled oscillations and synchronization between a pair of non-Hermitian, stochastic, opto-mechanical oscillators, levitated in vacuum. Each oscillator consists of a polystyrene microsphere trapped in a circularly polarized, counter-propagating Gaussian laser beam. Non-conservative, azimuthal forces, deriving from inhomogeneous optical spin, push the micro-particles out of thermodynamic equilibrium. For modest optical powers each particle shows a tendency towards orbital circulation. Initially, their stochastic motion is weakly correlated. As the power is increased, the tendency towards orbital circulation strengthens and the motion of the particles becomes highly correlated. Eventually, centripetal forces overcome optical gradient forces and the oscillators undergo a collective Hopf bifurcation. For laser powers exceeding this threshold, a pair of limit cycles appear, which synchronize due to weak optical and hydrodynamic interactions. In principle, arrays of such Non-Hermitian elements can be arranged, paving the way for opto-mechanical topological materials or, possibly, classical time crystals. In addition, the preparation of synchronized states in levitated optomechanics could lead to new and robust sensors or alternative routes to the entanglement of macroscopic objects.
Permanent Link: https://hdl.handle.net/11104/0348201