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Engineering and science have long used levitation of large objects as well as single atoms. Many researchers have been exploring a new frontier in the field of levitation. They are now able to create nano- and microparticles that are smaller than a hair's diameter, but contain billions of atoms in vacuum.
This new platform allows for both fundamental and applied research by allowing you to manipulate these objects and measure their translation and rotation with great precision.
"To give just a few examples, the high sensitivities and accelerations of levitated objects to external forces or accelerations fuel sensor development and search for new physics. The full control over friction and forces that affect the motion of these particles allows the testing of stochastic thermodynamic hypothesises. In addition, noise and friction can be reduced to a fundamental level by creating an ultrahigh vacuum. This opens up the possibility of quantum sensing and detection as well as exploring macro-quantum superpositions in large masses." Oriol Romero Isart, from the Institute of Quantum Optics and Quantum Information of Austria's Academy of Sciences and Department of Theoretical Physics of the University of Innsbruck.
The quantum ground state was cooled to the point of being a liquid crystal.
Quantum optics was first proposed in 2010 as a method to cool the motion of a nanoparticle. It uses an optical cavity to do this. These proposals were first developed experimentally, and then complemented by the creation of control mechanisms that are based on electrical, magnetic, and optical forces. Both active feedback cooling and optical cavity-based cooling have been successful in cooling the motions of dielectric levitated particles into the quantum ground state. This opens up the possibility for unexplored quantum mechanics.
Materials science, physics and sensors
High vacuum levitation of nanoobjects opens up new research opportunities and applications. It allows for isolation from the surrounding environment that was previously impossible. Carlos Gonzalez-Ballestero is a postdoctoral researcher at the University of Innsbruck's Department of Theoretical Physics. He says that "the current toolbox permits to levitate or control any type of nanoobject, such as magnets, metals and diamonds containing colour centers, graphene droplets and superfluid Helium, through optical, electrical and magnetic interactions". These interactions allow us to combine the internal degrees (e.g. "Phonons, magnons and excitons) to well-controlled external degrees (translation, rotation).
Clean testbeds for material sciences, such as levitated systems, allow matter to be analyzed and engineered in extreme conditions. Levitated systems can also be used to study non-equilibrium Physics. It is possible to limit noise and decoherence by extending control to all degrees of freedom of a levitated particles. This will allow for a new type of macroscopic quantum Physics (e.g. The preparation of macro-quantum superpositions of objects made up of billions of atoms and the probing for weak forces (e.g. These are the ones predicted by dark matter models and can be explored in new regimes. The use of ultrasensitive detection systems using levitated systems to detect forces opens up new commercial opportunities, such as gravimeters and pressure sensors, electric/magnetic fields sensors, and gravimeters.
Learn more about Quantum particles: Pulled, compressed
More information: Carlos Gonzalez Balesteros et al., Levitodynamics: control and levitation of microscopic objects under vacuum, Science (2021). www.science.org/doi/10.1126/science.abg3027 Journal information: Science Carlos Gonzalez-Ballestero et al, Levitodynamics: levitation and control of microscopic objects in vacuum,(2021). DOI: 10.1126/science.abg3027
