Related Experiment Video
Updated: Oct 9, 2025
08:03
Study of Protein Dynamics via Neutron Spin Echo Spectroscopy
Published on: April 13, 2022
2.3K
Critically Slow Operator Dynamics in Constrained Many-Body Systems
Johannes Feldmeier1, Michael Knap1
1Department of Physics and Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany and Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, D-80799 München, Germany.
Physical Review Letters
|December 22, 2021
Summary
In constrained quantum systems, conservation laws alter universal operator spreading. Researchers found a critical point in fracton chains exhibiting sub-ballistic growth, revealing a novel localization transition.
Area of Science:
- Quantum dynamics
- Many-body physics
- Condensed matter theory
Background:
- Far-from-equilibrium dynamics in quantum systems often follow universal principles.
- Ballistic spreading of local operators is a key characteristic of generic systems.
Purpose of the Study:
- To investigate how conservation laws modify universal dynamics in constrained many-body systems.
- To study operator growth in a dipole-conserving fracton chain using out-of-time-order correlations (OTOCs).
Main Methods:
- Analysis of operator growth via OTOCs in a dipole-conserving fracton chain.
- Identification of a critical point separating different dynamical phases.
- Numerical simulations using classically simulable automaton circuits.
Main Results:
- A critical point was identified where the out-of-time-order correlations (OTOCs) front moves sub-ballistically.
- This critical point signifies a transition between a ballistic and a dynamically frozen phase.
- The transition is linked to an underlying localization transition.
Conclusions:
- Conservation laws can drastically alter universal quantum dynamics in constrained systems.
- An effective description of the operator front as a biased random walk with long waiting times was derived.
- Numerical evidence supports the theoretical findings in automaton circuits.
More Related Videos
Related Concept Videos
01:23Equilibrium Conditions for a Particle
1.6K
When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
1.6K
01:20Types of Damping
6.8K
If the amount of damping in a system is gradually increased, the period and frequency start to become affected because damping opposes, and hence slows, the back and forth motion (the net force is smaller in both directions). If there is a very large amount of damping, the system does not even oscillate; instead, it slowly moves toward equilibrium. In brief, an overdamped system moves slowly towards equilibrium, whereas an underdamped system moves quickly to equilibrium but will oscillate about...
6.8K
01:26Constraints and Statical Determinacy
753
In structural engineering, the equilibrium of a system is not only determined by its equations of equilibrium but also with the help of constraints. Constraints refer to restrictions on the motion of a system. The proper combinations of constraints can minimize the total number of constraints needed to maintain a system in mechanical equilibrium. When this happens, the system is said to be statically determinate. For such systems, the unknown reaction supports can be estimated using equilibrium...
753
01:17Non-conservative Forces
8.4K
Non-conservative forces are dissipative forces such as friction or air resistance. These forces take energy away from a system as it progresses. Unlike conservative forces, non-conservative forces do not have potential energy associated with them. This is because the energy is lost to the system and cannot be turned into useful work later.
Also unlike their conservative counterparts, they are path-dependent; where the object starts and stops does matter. For example, a grinding wheel applies a...
Also unlike their conservative counterparts, they are path-dependent; where the object starts and stops does matter. For example, a grinding wheel applies a...
8.4K
01:18First Law: Particles in Two-dimensional Equilibrium
6.4K
Recall that a particle in equilibrium is one for which the external forces are balanced. Static equilibrium involves objects at rest, and dynamic equilibrium involves objects in motion without acceleration; but it is important to remember that these conditions are relative. For instance, an object may be at rest when viewed from one frame of reference, but that same object would appear to be in motion when viewed by someone moving at a constant velocity.
Newton's first law tells us about...
Newton's first law tells us about...
6.4K
01:21Rigid Body Equilibrium Problems - II
7.5K
A rigid body is in static equilibrium when the net force and the net torque acting on the system are equal to zero.
Consider two children sitting on a seesaw, which has negligible mass. The first child has a mass (m1) of 26 kg and sits at point A, which is 1.6 meters (r1) from the pivot point B; the second child has a mass (m2) of 32 kg and sits at point C. How far from the pivot point B should the second child sit (r2) to balance the seesaw?
Consider two children sitting on a seesaw, which has negligible mass. The first child has a mass (m1) of 26 kg and sits at point A, which is 1.6 meters (r1) from the pivot point B; the second child has a mass (m2) of 32 kg and sits at point C. How far from the pivot point B should the second child sit (r2) to balance the seesaw?
7.5K