The quantum state of a rotating superfluid can be emitted in three ways.

In the study, it was observed that quadruple-quantity vortices have three distribution modes, leading to three different patterns. Credit: Physical examination letters (2023). DOI: 10.1103/PhysRevLett.131.221602

According to a recent study from the University of Helsinki, published In the journal Physical examination lettersa vortex of a superfluid whose volume is quadrupled has three ways of partitioning as a function of temperature.

The fluid changes to a. near the absolute zero point of (about -273°C) Internal resistance forces, such as friction, disappear. At this point, the behavior of the fluid can no longer be described using ; Instead, quantum physics must be applied.

When a superfluid is spun, the resulting rotation should never slow down because the superfluid has no viscosity or friction. It has been tested. using helium in very slow rotation, and it was observed that the superfluid, however, eventually stopped.

This is because the vorticity of a superfluid is quantized: the overall vorticity breaks up into smaller vortices—the angular momentum is both quantized and constant and therefore does not vanish.

Circulation is restricted.

A regular such as water flowing out of a sink — can spin on its axis at any speed, while A quantized vertex is always proportional to an integer. This number is called winding number. The winding numbers of individual and quadrupled vortices are one and four, respectively.

A quadruple quantized vortex easily splits into four singly quantized vortices because a quadruple quantized vortex is more unstable due to the significantly lower energy of the system after splitting. Less energy means a more stable system.

Xin Li, a doctoral researcher from the University of Helsinki, investigated the quadruple quantized vortex splitting process in his recent work. What happens when an unstable, quadruple volume vortex is allowed to exist at three different temperatures, all still very close to absolute zero?

Three temperatures, three dispensing methods

In the study, it was observed that quadruple-quantity vortices have three distribution modes, leading to three different patterns. Although these patterns were theoretically identified in previous studies, the results show for the first time that temperature leads to different distribution processes.

The distribution was modeled by applying a relatively new theory to the phenomenon, called gauge/gravity duality or holography. This allows a systematic examination of dual temperature effects in a manner that closely resembles a realistic situation.

The study shows that there are two observed patterns in the lower temperature range, while a third pattern may emerge as temperatures increase further. Empirically, two of them The pattern has been observed so far, and the researchers suggest that at higher temperatures, a new pattern may emerge.

More information:
Shanquan Lin et al., Quadruple Volume Vortex Heating: Splitting Patterns and Dynamic Transfer, Physical examination letters (2023). DOI: 10.1103/PhysRevLett.131.221602. On arXiv: DOI: 10.48550/arxiv.2311.01316

Reference: Study shows quantum state of rotating superfluid can be emitted in three ways (2024, February 16) Accessed on February 17, 2024 at https://phys.org/news/2024-02-quantum-state-rotating- Retrieved from superfluid-discharge.html

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