Time crystal emerges in acoustic tweezers
System could shed light on emergent periodic phenomena in biological systems The post Time crystal emerges in acoustic tweezers appeared first on Physics World .
In a groundbreaking experiment, researchers at New York University have created a simple example of a classical time crystal using acoustic tweezers. This system, which involves the use of sound waves to trap and manipulate objects, has the potential to shed light on emergent periodic phenomena in biological systems and even offer a way to measure mass with high precision.
Acoustic tweezers are the acoustic analogue of optical tweezers, utilizing sound waves to create a potential-energy well that can hold an object in place. In the case of a single trapped object, this process is dissipationless, meaning the particle neither gains nor loses energy from the trapping wave. However, when two objects are levitated in adjacent nodes of an ultrasound standing wave, the situation becomes far more intriguing.
David Grier, a researcher at NYU, along with graduate student Mia Morrell and undergraduate Leela Elliott, demonstrated that pairs of nonidentical particles can spontaneously begin to oscillate. This occurs because the particles harvest energy from the standing wave, leading to a periodic motion that appears to violate NewtonтАЩs third law. Normally, one might expect the particles to remain stationary if they are identical, as their interactions would cancel out. But when the particles differ in size, material, or any other property that affects acoustic scattering, they exhibit unexpected behavior.
The researchers were surprised to find that the oscillation is not constrained by the requirement for momentum conservation, as stated by NewtonтАЩs third law. This apparent violation of a fundamental physical principle has led them to classify the system as a very simple type of emergent active matter known as a time crystal. The periodic oscillation in this system has a frequency that is parametrized only by the properties of the particles and is independent of the trapping frequency.
The discovery of this classical time crystal in an acoustic tweezers setup could offer valuable insights into emergent periodic phenomena observed in nature. Many biological systems exhibit complex behaviors that arise from the interactions of individual components, and understanding the principles behind these phenomena could lead to new discoveries in fields such as biology, chemistry, and materials science.
Moreover, the researchers believe that their system could provide an easy way to measure mass with high precision. By analyzing the oscillations of the particles in the acoustic tweezers, it may be possible to determine the mass of the objects with a level of accuracy that is currently unattainable using traditional methods.
This experiment not only highlights the potential of acoustic tweezers as a versatile tool for studying physical systems but also underscores the importance of interdisciplinary research. By combining expertise in acoustics, physics, and materials science, the researchers have made a significant contribution to our understanding of emergent phenomena and the behavior of matter under non-equilibrium conditions.
As the field of time crystals continues to develop, the work of Grier and his colleagues serves as a foundation for further exploration. The ability to create and manipulate time crystals in a controlled environment could pave the way for the discovery of new materials with unique properties and the development of novel technologies. The potential applications of this research are vast, and the insights gained from studying these intriguing systems are likely to extend far beyond the realm of physics.
