Related Experiment Video
Updated: Sep 8, 2025

11:41
Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
23.4K
Driven toroidal helix as a generalization of the Kapitza pendulum
J F Gloy1, A Siemens1, P Schmelcher1,2
1Zentrum für Optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg Germany.
Physical Review. E
|June 16, 2022
Summary
A driven toroidal helix system generalizes the Kapitza pendulum. Analytical and numerical studies reveal fixed point stability and chaotic dynamics, including directed transport.
Area of Science:
- Classical mechanics
- Nonlinear dynamics
- Physics of oscillations
Background:
- The Kapitza pendulum, a classical pendulum with an oscillating pivot, exhibits unique stability properties.
- Generalizing classical systems can reveal novel dynamics and phenomena.
- Understanding driven nonlinear systems is crucial in various physics domains.
Purpose of the Study:
- To investigate a driven toroidal helix system as a generalization of the Kapitza pendulum.
- To analyze the stability of static fixed points in the toroidal helix model.
- To explore deviations from Kapitza pendulum behavior, including chaotic transitions and directed transport.
Main Methods:
- Analytical investigation of fixed point stability.
- Numerical simulations to compare with analytical results.
- Phase space analysis to identify deviations and transport phenomena.
Main Results:
- The driven toroidal helix system reduces to the Kapitza pendulum in the limit of vanishing helix radius.
- Two dominant static fixed points, analogous to the Kapitza pendulum, are identified and their stability analyzed.
- Deviations from Kapitza pendulum behavior include unusual transitions to chaos and effective directed transport.
Conclusions:
- The driven toroidal helix serves as a valuable generalization of the Kapitza pendulum.
- Stability analysis provides insights into the system's behavior under varying parameters.
- The emergence of chaos and directed transport highlights the rich dynamics of this generalized system.
Related Concept Videos
Torsional Pendulum
5.9K
A torsional pendulum involves the oscillation of a rigid body in which the restoring force is provided by the torsion in the string from which the rigid body is suspended. Ideally, the string should be massless; practically, its mass is much smaller than the rigid body's mass and is neglected.
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played...
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played...
5.9K
Toroids
3.1K
A toroid is a closely wound donut-shaped coil constructed using a single conducting wire. In general, it is assumed that a toriod consists of multiple circular loops perpendicular to its axis.
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb...
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb...
3.1K
Torque On A Current Loop In A Magnetic Field
4.6K
The most common application of magnetic force on current-carrying wires is in electric motors. These consist of loops of wire, which are placed between the magnets with a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate, thus converting electrical energy to mechanical energy.
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
4.6K
Simple Pendulum
5.0K
A simple pendulum consists of a small diameter ball suspended from a string, which has negligible mass but is strong enough to not stretch. In our daily life, pendulums have many uses, such as in clocks, on a swing set, and on a sinker on a fishing line.
The period of a simple pendulum depends on two factors: its length and the acceleration due to gravity. The period is completely independent of any other factors, such as mass or maximum displacement. For small displacements, a pendulum...
The period of a simple pendulum depends on two factors: its length and the acceleration due to gravity. The period is completely independent of any other factors, such as mass or maximum displacement. For small displacements, a pendulum...
5.0K
Motion Of A Charged Particle In A Magnetic Field
5.2K
A charged particle experiences a force when moving through a magnetic field. Consider the field to be uniform and the charged particle to move perpendicular to it. If the field is in a vacuum, the magnetic field is the dominant factor determining the motion. Since the magnetic force is perpendicular to the direction of motion, a charged particle follows a curved path. The particle continues to follow this curved path until it forms a complete circle. Another way to look at this is that the...
5.2K
Physical Pendulum
1.9K
When a rigid body is hanging freely from a fixed pivot point and is displaced, it oscillates similar to a simple pendulum and is known as a physical pendulum. The period and angular frequency of a physical pendulum are obtained by using the small-angle approximation and drawing parallels with a spring-mass system. The small-angle approximation (sinθ=θ) is valid up to about 14°.
When dealing with complicated systems, the mass moment of inertia is an important parameter, as it...
When dealing with complicated systems, the mass moment of inertia is an important parameter, as it...
1.9K

