Theoretical physicists, led by Oriol Romero-Isart from the Institute for Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences (ÖAW) and the University of Innsbruck, have proposed an experiment to observe macroscopic quantum effects. The experiment involves an optically levitated nanoparticle, cooled to its ground state, evolving in a non-optical potential created by electrostatic or magnetic forces.
The process is expected to rapidly generate a macroscopic quantum superposition state. The proposal, supported by the European Union’s Q-Xtreme project, aims to overcome challenges such as fast experimental runs and minimal use of laser light.
Quantum Physics Experiment Proposal: Observing Macroscopic Quantum Effects in the Dark
Theoretical physicists have proposed a groundbreaking experiment to observe macroscopic quantum superposition states. The experiment involves an object evolving in a potential created through electrostatic or magnetic forces, which is expected to generate a macroscopic quantum superposition state rapidly and reliably. The proposal was published in a recent paper in Physical Review Letters.
The boundary between the quantum world and everyday reality remains unclear. The more massive an object, the more localized it becomes when made quantum by cooling down its motion to absolute zero. The research team, led by Oriol Romero-Isart from the Institute for Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences (ÖAW) and the Department of Theoretical Physics at the University of Innsbruck, proposes an experiment involving an optically levitated nanoparticle. This nanoparticle, cooled to its ground state, evolves in a non-optical (“dark”) potential created by electrostatic or magnetic forces, which is expected to generate a macroscopic quantum superposition state.
The Role of Laser Light and the Dark Potential
Laser light can cool a nanoscale-sized glass sphere to its motional ground state. However, when left alone, such glass spheres quickly heat up due to bombardment by air molecules and scattering incoming light, leaving the quantum regime. To avoid this, the researchers propose letting the sphere evolve in the dark, with the light switched off, guided solely by nonuniform electrostatic or magnetic forces. This evolution is not only fast enough to prevent heating by stray gas molecules but also lifts the extreme localization and imprints unequivocally quantum features.
Overcoming Practical Challenges
The paper in Physical Review Letters also discusses how this proposal circumvents the practical challenges of these types of experiments. These challenges include the need for fast experimental runs, minimal use of laser light to avoid decoherence, and the ability to quickly repeat experimental runs with the same particle. These considerations are crucial in mitigating the impact of low-frequency noise and other systematic errors.
Collaboration with Q-Xtreme and Future Prospects
The proposal has been extensively discussed with experimental partners in Q-Xtreme, an ERC Synergy Grant project financially supported by the European Union. The proposed method aligns with current developments in their labs, and they should soon be able to test the protocol with thermal particles in the classical regime. This will be very useful to measure and minimize sources of noise when lasers are off, according to the theory team of Oriol Romero-Isart. They believe that while the ultimate quantum experiment will be unavoidably challenging, it should be feasible as it meets all the necessary criteria for preparing these macroscopic quantum superposition states.
“The proposed method is aligned with current developments in their labs and they should soon be able to test our protocol with thermal particles in the classical regime, which will be very useful to measure and minimize sources of noise when lasers are off,” says the theory team of Oriol Romero-Isart. “We believe that while the ultimate quantum experiment will be unavoidably challenging, it should be feasible as it meets all the necessary criteria for preparing these macroscopic quantum superposition states.” – Oriol Romero-Isart.
Summary
Theoretical physicists have proposed an experiment to observe macroscopic quantum effects, using an optically levitated nanoparticle cooled to its ground state and evolved in a non-optical potential created by electrostatic or magnetic forces. This method, which involves minimal use of light to avoid decoherence and is fast enough to prevent heating by stray gas molecules, is expected to generate a macroscopic quantum superposition state, offering a new way to explore the boundary between everyday reality and the quantum world.
- Theoretical physicists, led by Oriol Romero-Isart from the Institute for Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences (ÖAW) and the University of Innsbruck, have proposed a pioneering experiment to observe macroscopic quantum effects.
- The experiment involves an optically levitated nanoparticle, cooled to its ground state, evolving in a non-optical potential created by electrostatic or magnetic forces. This is expected to rapidly generate a macroscopic quantum superposition state.
- The nanoparticle is cooled using laser light, but to prevent it from heating up and leaving the quantum regime, the light is switched off and the particle is guided solely by nonuniform electrostatic or magnetic forces.
- The experiment is designed to be fast enough to prevent heating by stray gas molecules and to imprint unequivocally quantum features.
- The proposal also addresses practical challenges such as the need for fast experimental runs, minimal use of laser light to avoid decoherence, and the ability to quickly repeat experimental runs with the same particle.
- The proposal has been discussed with experimental partners in Q-Xtreme, a project financially supported by the European Union. The team believes that the ultimate quantum experiment, while challenging, should be feasible.
