Scientists have put forward a new experimental protocol that could lead to the creation of large-scale quantum superposition states. Led by Oriol Romero-Isart from the Institute for Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences, the team suggests evolving a suspended and cooled optically nanoparticle in a non-optical potential created by electrostatic or magnetic forces, rather than relying on laser light.
The researchers have successfully developed a method using laser light to cool a tiny glass sphere to its lowest energy state. However, the spheres heat up when left alone due to interactions with air molecules and scattered light, which compromises their quantum properties.
To overcome this challenge, the proposed protocol allows the sphere to evolve without light, guided solely by nonuniform electrostatic or magnetic forces. This rapid evolution prevents heating from stray gas molecules and introduces unique quantum characteristics to the system.
The study tackles the practical issues associated with experiments of this nature. Swift experimental processes, minimizing laser light usage, and the ability to repeat experiments with the same particle are all crucial factors in reducing low-frequency noise and other systematic errors.
The proposal has been extensively discussed with partners in the Q-Xtreme project, an ERC Synergy Grant project funded by the European Union.
According to the theory team led by Oriol Romero-Isart, this method aligns with current developments in their labs, paving the way for testing the protocol with thermal particles in the classical regime. This will aid in measuring and minimizing sources of noise when lasers are not in use.
While the team acknowledges the challenges of conducting the ultimate quantum experiment, they believe that by meeting all the necessary criteria, creating macroscopic quantum superposition states should be feasible.
Journal Reference:
M. Roda-Llordes, A. Riera-Campeny, D. Candoli, P. T. Grochowski, and O. Romero-Isart. Macroscopic Quantum Superpositions via Dynamics in a Wide Double-Well Potential. Phys. Rev. Lett. DOI: 10.1103/PhysRevLett.132.023601