Related Experiment Video
Updated: Dec 25, 2025
06:42
Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
9.5K
Simulating Nonlinear Dynamics of Collective Spins via Quantum Measurement and Feedback
Manuel H Muñoz-Arias1, Pablo M Poggi1, Poul S Jessen2
1Center for Quantum Information and Control, CQuIC, Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA.
Physical Review Letters
|April 4, 2020
Summary
This study demonstrates a feedback method to simulate quantum chaos using spin ensembles. The technique recovers classical dynamics and explores the emergence of chaos from complex quantum systems.
Area of Science:
- Quantum physics
- Quantum chaos
- Many-body dynamics
Background:
- Simulating complex quantum systems is challenging.
- Quantum chaos provides a framework for understanding complex dynamics.
- Measurement-based feedback offers a novel simulation approach.
Purpose of the Study:
- To develop and analyze a measurement-based feedback method for simulating quantum many-body dynamics.
- To investigate the emergence of classical chaos from quantum systems.
- To explore the robustness of this simulation method against decoherence.
Main Methods:
- Weak collective measurement on spin ensembles.
- Global rotations conditioned on measurement outcomes.
- Analytical derivation of quantum trajectory behavior and Lyapunov exponents.
Main Results:
- Identified a regime where quantum trajectories recover the classical limit.
- Demonstrated the transition from noisy quantum dynamics to deterministic chaos.
- Analyzed the impact of decoherence on the simulation fidelity.
Conclusions:
- The proposed method robustly simulates quantum chaos in spin ensembles.
- This technique is suitable for experimental platforms like atom-light interfaces.
- Provides insights into the quantum-to-classical transition in chaotic systems.
Related Concept Videos
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.2K
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
1.2K
01:08Spin–Spin Coupling Constant: Overview
1.4K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
1.4K
01:03Atomic Nuclei: Nuclear Spin State Overview
1.8K
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
1.8K
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.4K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.4K
01:08NMR Spectroscopy: Spin–Spin Coupling
2.8K
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...
2.8K
01:17Spin–Spin Coupling: One-Bond Coupling
1.3K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.3K