Related Experiment Video
Updated: Mar 27, 2026
07:56
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
9.1K
Helicity conservation under quantum reconnection of vortex rings
Simone Zuccher1, Renzo L Ricca2
1Department of Computer Science, U. Verona, Ca' Vignal 2, Strada Le Grazie 15, 37134 Verona, Italy.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|January 15, 2016
Summary
Quantum reconnection conserves self-helicity in interacting vortex rings. While vortex core structure changes, total length peaks at reconnection, with writhe and twist helicity remaining constant.
Area of Science:
- Quantum turbulence
- Vortex dynamics
Background:
- Interactions between vortex rings are fundamental in quantum turbulence.
- Understanding the topological properties of these interactions is crucial.
Purpose of the Study:
- To investigate the conservation of self-helicity during quantum reconnection of two interacting vortex rings.
- To analyze the behavior of writhe and twist helicity during this process.
Main Methods:
- Simulations using the three-dimensional Gross-Pitaevskii equation.
- Resolving the fine structure of vortex cores.
- Calculating topological invariants like writhe, total torsion, and intrinsic twist.
- Employing two independent methods to compute self-helicity.
Main Results:
- Self-helicity of the vortex system is conserved during quantum reconnection.
- The total length of the vortex system reaches a maximum at the reconnection time.
- Writhe helicity and twist helicity remain unchanged throughout the reconnection process.
- Geometric quantities confirm the conservation of topological information.
Conclusions:
- Quantum reconnection of interacting vortex rings preserves overall self-helicity.
- The study clarifies the distinct behaviors of writhe and twist helicity during reconnection.
- This provides a deeper understanding of topological conservation in quantum fluid dynamics.
Related Concept Videos
01:09Conservation of Angular Momentum
16.5K
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Considering a system that consists of n tiny particles, the angular momentum of any tiny particle may change, but the system's total angular momentum would remain constant. The principle of conservation of angular momentum only considers the net external torque acting on the system. While there are internal forces exerted by different particles within the system that also produce...
16.5K
01:18Conservation of Angular Momentum: Application
12.5K
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Examples of such systems include a freely spinning bicycle tire that slows over time due to torque arising from friction, or the slowing of Earth's rotation over millions of years due to frictional forces exerted on tidal deformations. However in the absence of a net external torque, the angular momentum remains conserved. The conservation of angular momentum principle requires a...
12.5K
01:26Divergence and Curl of Magnetic Field
4.2K
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
4.2K
01:25Divergence and Curl of Electric Field
7.6K
The divergence of a vector is a measure of how much the vector spreads out (diverges) from a point. For example, an electric field vector diverges from the positive charge and converges at the negative charge. The divergence of an electric field is derived using Gauss's law and is equal to the charge density divided by the permittivity of space. Mathematically, it is expressed as
7.6K
01:14Conservation of Energy in Control Volume
1.2K
Consider a turbine operating under steady-flow conditions. The control volume is drawn around the turbine, with fluid entering at one point and exiting at another. The turbine extracts energy from the fluid, which performs mechanical work (shaft work).
For steady flow systems, the time derivative of the stored energy becomes zero since there is no energy accumulation within the control volume. This simplifies the energy equation to:
For steady flow systems, the time derivative of the stored energy becomes zero since there is no energy accumulation within the control volume. This simplifies the energy equation to:
1.2K
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.7K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
1.7K