Periodic Reporting for period 3 - Q-Xtreme (Macroscopic Quantum Superpositions)
Okres sprawozdawczy: 2024-05-01 do 2025-10-31
Project Q-Xtreme is guided by a critical question: do the principles of quantum physics apply to macroscopic objects irrespective of their size? Addressing this issue holds theoretical interest and potential practical benefits. By delving into the fundamentals of quantum physics, we aim to broaden our knowledge of the physical world and advance technologies across several disciplines. The primary objective of Q-Xtreme is to experimentally prepare and control a levitated object in a quantum superposition, where it behaves as if it were in two places at once. This extends previous tests of the quantum superposition principle to unprecedented macroscopic scales.
Historically, macroscopic quantum superpositions have been confirmed for objects as large as organic molecules, which contain thousands of atoms. With Q-Xtreme, our goal is to extend these verifications to objects comprising billions of atoms, exceeding current benchmarks by at least five orders of magnitude in mass. The approach involves quantum control of the center-of-mass motion of a levitated nanoparticle in ultra-high vacuum using a combination of optical, electrical, and magnetic forces. The execution of these ambitious goals is made possible by our synergy team, which combines leading expertise in photonics, nanotechnology, optoelectronics, and quantum technology.
The implications of the project are broad, offering potential insights into the relationship between quantum physics and gravity, and contributing to our understanding of dark matter and dark energy models. The practical applications that could arise from achieving macroscopic quantum superpositions are also noteworthy, such as improved inertial force sensing, measurements of short-range interactions, and gravitational physics.
Historically, macroscopic quantum superpositions have been confirmed for objects as large as organic molecules, which contain thousands of atoms. With Q-Xtreme, our goal is to extend these verifications to objects comprising billions of atoms, exceeding current benchmarks by at least five orders of magnitude in mass. The approach involves quantum control of the center-of-mass motion of a levitated nanoparticle in ultra-high vacuum using a combination of optical, electrical, and magnetic forces. The execution of these ambitious goals is made possible by our synergy team, which combines leading expertise in photonics, nanotechnology, optoelectronics, and quantum technology.
The implications of the project are broad, offering potential insights into the relationship between quantum physics and gravity, and contributing to our understanding of dark matter and dark energy models. The practical applications that could arise from achieving macroscopic quantum superpositions are also noteworthy, such as improved inertial force sensing, measurements of short-range interactions, and gravitational physics.
During the reporting period, the consortium made significant progress toward realizing macroscopic quantum superpositions. Experimentally, we achieved quantum ground-state cooling of a levitated nanoparticle in ultra-high vacuum and demonstrated the first quantum delocalization of a nanoparticle beyond its zero-point motion. We performed experiments showing thermal expansion in engineered dark potentials, including inverted harmonic potentials, and demonstrated ultrastrong linear optomechanical coupling as well as cavity-mediated long-range interactions between levitated particles. In parallel, we achieved magnetic levitation and remote sensing of superconducting microspheres and developed novel particle trapping mechanisms, including levitation and motion control on a chip and fiber-based particle loading in high vacuum. Finally, we also demonstrated control in the quantum regime of rotational degrees of freedom of levitated nanoparticles.
From a theoretical standpoint, the consortium advanced the quantum control of levitated systems by developing protocols for generating and certifying non-Gaussian states, theories for optical detection and decoherence control, and a numerical simulator for nanoparticle dynamics in nonharmonic potentials.
From a theoretical standpoint, the consortium advanced the quantum control of levitated systems by developing protocols for generating and certifying non-Gaussian states, theories for optical detection and decoherence control, and a numerical simulator for nanoparticle dynamics in nonharmonic potentials.
The quantum control achieved within the Synergy consortium—encompassing both the center-of-mass and rotational degrees of freedom of levitated nanoparticles, as well as their dynamics through the engineering of optical and nonoptical potentials—already goes beyond the current state of the art. Moving forward, our focus is twofold. First, we aim to demonstrate quantum delocalization of the nanoparticle’s center-of-mass motion, corresponding to motional quantum squeezing at levels at least one order of magnitude larger than the zero-point motion (beyond 20 dB of squeezing). This milestone, essential for preparing macroscopic quantum superpositions in non-Gaussian motional states, would mark a major advance in quantum science.
In parallel, we seek to measure and minimize decoherence in dark potentials to levels several orders of magnitude lower than those encountered when nanoparticles are optically illuminated and experience photon recoil heating. Ideally, these experiments will be performed with nanoparticles cooled to their quantum ground state in optical potentials that that are then released to dark potentials. Achieving these two goals will pave the way toward the ultimate objective of Q-Xtreme: the preparation and certification of macroscopic quantum superpositions of a levitated nanoparticle.
In parallel, we seek to measure and minimize decoherence in dark potentials to levels several orders of magnitude lower than those encountered when nanoparticles are optically illuminated and experience photon recoil heating. Ideally, these experiments will be performed with nanoparticles cooled to their quantum ground state in optical potentials that that are then released to dark potentials. Achieving these two goals will pave the way toward the ultimate objective of Q-Xtreme: the preparation and certification of macroscopic quantum superpositions of a levitated nanoparticle.