Polaritons are quantum particles that consist of a photon and an exciton, another quasiparticle, combining light and matter in a curious union that opens up a multitude of possibilities in next-generation devices.
The researchers have shown that geometrically coupled polariton condensates, which appear in semiconductor devices, are capable of simulating molecules with various properties.
Ordinary molecules are groups of atoms bound together with molecular bonds, and their physical properties differ from those of their constituent atoms quite drastically: consider the water molecule, H2O, and elemental hydrogen and oxygen.
“In our work, we show that clusters of interacting polaritonic and photonic condensates can form a range of exotic and entirely distinct entities – ‘molecules’ – that can be manipulated artificially,” said first author Alexander Johnston, from Cambridge Department of Applied Mathematics and Theoretical Physics. “These artificial molecules possess new energy states, optical properties, and vibrational modes from those of the condensates comprising them.”
Johnston and his colleagues – Kirill Kalinin from DAMTP and Professor Natalia Berloff, who holds joint positions at Cambridge and Skoltech – were running numerical simulations of two, three, and four interacting polariton condensates, when they noticed some curious asymmetric stationary states in which not all of the condensates have the same density in their ground state.
“Upon further investigation, we found that such states came in a wide variety of different forms, which could be controlled by manipulating certain physical parameters of the system,” said Johnston. “This led us to propose such phenomena as artificial polariton molecules and to investigate their potential uses in quantum information systems.”
Reproduced courtesy of the University of Cambridge