Scanning superfluid-turbulence cascade by its low-temperature cutoff

Area of Science:

• Quantum turbulence
• Superfluidity
• Low-temperature physics

Background:

• A recently proposed scenario describes the transformation of the Kolmogorov cascade into the Kelvin-wave cascade.
• Understanding the low-temperature behavior of superfluid turbulence is crucial for theoretical and experimental physics.

Purpose of the Study:

• To develop a theory of low-temperature cutoff for superfluid turbulence.
• To predict the behavior of quantized vortex line density (L) controlled by the frictional coefficient (alpha(T)).
• To experimentally validate the scenario of low-temperature superfluid turbulence and quantify the Kelvin-wave cascade spectrum.

Main Methods:

• Developing a theoretical framework based on the Kolmogorov to Kelvin-wave cascade transformation.
• Analyzing the relationship between quantized vortex line density (L) and the frictional coefficient (alpha(T)).
• Comparing theoretical predictions with experimental data from Walmsley et al. (2007).

Main Results:

• The theory predicts specific behavior of quantized vortex line density (L) influenced by the frictional coefficient (alpha(T)).
• The curve ln L(lnalpha) reveals four distinct wave number regions, reflecting the cascade's structure.
• Excellent agreement was found between the theory and experimental measurements of L(T) down to 0.08 K.

Conclusions:

• The experimental validation supports the proposed scenario of low-temperature superfluid turbulence.
• The study successfully quantifies the Kelvin-wave cascade spectrum.
• The findings provide a robust theoretical and experimental foundation for understanding superfluid turbulence at low temperatures.