New Quasi-Particle Bridges Microwave and Optical Domains, Enabling Coherent Information Transfer

Researchers from the Paul-Drude-Institut in Berlin, Germany, and the Instituto Balseiro in Bariloche, Argentina, have made a significant discovery in the field of quantum physics. They have demonstrated the emergence of a new quasi-particle called a phonoriton, which is a combination of a photon (quantum of light), a phonon (quantum of sound), and a semiconductor exciton. This discovery has the potential to enable the coherently convert information between the optical and microwave domains, which could benefit various fields such as photonics, optomechanics, and optical communication technologies.

The researchers drew inspiration from the transfer of energy between two coupled oscillators, such as two pendulums connected by a spring. In the strong-coupling regime, energy continuously oscillates between the two oscillators. In the case of photonic or electronic quantum states, the strong-coupling regime is crucial for controlling and swapping quantum states.

However, in hybrid quantum systems, there is a need for coherent information transfer between oscillators with different frequencies. For example, quantum computers operate with microwave qubits, while quantum information is efficiently transferred using near infrared photons. To achieve this bidirectional and coherent transfer of information, a third particle that can efficiently couple to both the microwave qubits and photons is needed. One such candidate is the vibration of the lattice, known as a phonon.

The researchers created polaritons, which are a result of strong coupling between photons and excitons, in a patterned microcavity resonator. By injecting more polaritons into the trap, they created two polariton condensates. When the energy splitting between the two light fluids matched the phonon energy, the synchronization of the two polariton fluids occurred. This synchronization was due to a combination of interactions between polaritons and the efficient transfer of polaritons mediated by phonons.

The researchers were able to control the device and inject phonons into the trap using a piezoelectric transducer. In the presence of the injected phonons, the phonoriton spectrum transformed into a comb of narrow resonances, demonstrating bidirectional microwave-to-optical conversion.

This work opens up new possibilities for coherent information transfer between the microwave and optical domains. By harnessing the properties of phonoritons, advancements in photonics, optomechanics, and optical communication technologies can be made.

– Nature Communications: