Related Experiment Video
Updated: Jul 25, 2026
11:19
Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
Time evolution of a single spin inhomogeneously coupled to an interacting spin environment
Zhen Huang1, Gehad Sadiek, Sabre Kais
1Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
The Journal of Chemical Physics
|April 22, 2006
Summary
The decay rate of single spin oscillations depends on exchange coupling strength. Decoherence time varies with coupling ratios, showing Gaussian, exponential, or power-law decay. Spin oscillations propagate into the environment.
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Spin dynamics
Background:
- Understanding spin dynamics in quantum systems is crucial for developing quantum technologies.
- Spin baths significantly influence the coherence of individual spins, a key challenge in quantum information processing.
Purpose of the Study:
- To investigate the time evolution of a single spin interacting with a spin bath.
- To analyze how exchange coupling strengths affect spin decoherence and oscillation decay rates.
Main Methods:
- Evaluating the spin correlator of a single spin.
- Modeling the spin bath using the XY Hamiltonian.
- Analyzing the influence of exchange coupling (J and J(')), anisotropic parameters, magnetic fields, and temperature.
Main Results:
- Spin oscillation decay rate is highly sensitive to the relative magnitudes of J and J(').
- Decay profiles transition from Gaussian (J(') ≈ J) to exponential (J(') > J) and power-law (J(') < J).
- Spin oscillations propagate from the central spin into the environment with a measurable speed.
Conclusions:
- The interplay between local and environmental spin couplings dictates decoherence pathways.
- Environmental parameters like temperature and magnetic fields modulate the spin decay dynamics.
- This study provides insights into controlling spin coherence in complex quantum environments.
More Related Videos
Related Concept Videos
01:03Atomic Nuclei: Nuclear Spin State Overview
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...
01:23Atomic Nuclei: Nuclear Relaxation Processes
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. This...
01:08NMR Spectroscopy: Spin–Spin Coupling
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 in...
01:08Spin–Spin Coupling Constant: Overview
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 have a...
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 have a...
01:17Spin–Spin Coupling: One-Bond Coupling
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,...
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...