Enhanced Coupling of Electron and Nuclear Spins by Quantum Tunneling Resonances

This paper seeks to discuss why information theory is so important. What is information, knowledge is interaction of human mind and information, but there is a difference between information theory and knowledge theory. Look into information and particle theory and see how information must have its roots in particle theory. This leads to the concept of spatial dimensions, information density, complexity, particle density, can there be particle complexity, and re-looking at the double slit experiment and quantum tunneling. Information functions/ relations are discussed.

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Dualism QM and GR

10.31219/osf.io/8nzwd ◽

2019 ◽

Author(s):

Vitaly Kuyukov

Keyword(s):

Quantum Mechanics ◽

General Theory ◽

Noncommutative Geometry ◽

Quantum Tunneling ◽

Closed Surface ◽

Theory Of Relativity ◽

General Theory Of Relativity ◽

Surface Integral ◽

Definition Of

Quantum tunneling of noncommutative geometry gives the definition of time in the form of holography, that is, in the form of a closed surface integral. Ultimately, the holography of time shows the dualism between quantum mechanics and the general theory of relativity.

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Strong Coupling of Electron and Nuclear Spins: Outlook and Prospects

10.1093/oso/9780198807308.003.0011 ◽

2018 ◽

Author(s):

M. M. Glazov

Keyword(s):

Energy Spectrum ◽

Charge Carrier ◽

Strong Coupling ◽

Nuclear Spin ◽

Spin Dynamics ◽

Spin Polaron ◽

Nuclear Spins ◽

Deep Impurity ◽

Impurity Centers ◽

Ordered State

In this chapter, some prospects in the field of electron and nuclear spin dynamics are outlined. Particular emphasis is put ona situation where the hyperfine interaction is so strong that it leads to a qualitative rearrangement of the energy spectrum resulting in the coherent excitation transfer between the electron and nucleus. The strong coupling between the spin of the charge carrier and of the nucleus is realized, for example in the case of deep impurity centers in semiconductors or in isotopically purified systems. We also discuss the effect of the nuclear spin polaron, that is ordered state, formation at low enough temperatures of nuclear spins, where the orientation of the carrier spin results in alignment of the spins of nucleus interacting with the electron or hole.

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Electron Spin Decoherence by Nuclei

10.1093/oso/9780198807308.003.0007 ◽

2018 ◽

Author(s):

M. M. Glazov

Keyword(s):

Electron Spin ◽

Spin Dynamics ◽

Magnetic Moments ◽

Host Lattice ◽

Spin Model ◽

Relaxation Processes ◽

Nuclear Spins ◽

Model Calculations ◽

Spin Decoherence ◽

Quantum Mechanical Approach

The discussion of the electron spin decoherence and relaxation phenomena via the hyperfine interaction with host lattice spins is presented here. The spin relaxation processes processes limit the conservation time of spin states as well as the response time of the spin system to external perturbations. The central spin model, where the spin of charge carrier interacts with the bath of nuclear spins, is formulated. We also present different methods to calculate the spin dynamics within this model. Simple but physically transparent semiclassical treatment where the nuclear spins are considered as largely static classical magnetic moments is followed by more advanced quantum mechanical approach where the feedback of electron spin dynamics on the nuclei is taken into account. The chapter concludes with an overview of experimental data and its comparison with model calculations.

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Quantum Tunneling

10.1093/oso/9780198808275.003.0014 ◽

2017 ◽

Author(s):

Frank S. Levin

Keyword(s):

Quantum Tunneling ◽

Alpha Particles ◽

Attractive Potential ◽

Scanning Tunneling ◽

Finite Width ◽

Potential Well ◽

Surface Molecules ◽

Repulsive Coulomb ◽

The Subject ◽

The One

Quantum tunneling, wherein a quanject has a non-zero probability of tunneling into and then exiting a barrier of finite width and height, is the subject of Chapter 13. The description for the one-dimensional case is extended to the barrier being inverted, which forms an attractive potential well. The first application of this analysis is to the emission of alpha particles from the decay of radioactive nuclei, where the alpha-nucleus attraction is modeled by a potential well and the barrier is the repulsive Coulomb potential. Excellent results are obtained. Ditto for the similar analysis of proton burning in stars and yet a different analysis that explains tunneling through a Josephson junction, the connector between two superconductors. The final application is to the scanning tunneling microscope, a device that allows the microscopic surfaces of solids to be mapped via electrons from the surface molecules tunneling into the tip of the STM probe.

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A simulation study investigating potential diffusion-based MRI signatures of microstrokes

Scientific Reports ◽

10.1038/s41598-021-93503-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Rafat Damseh ◽

Yuankang Lu ◽

Xuecong Lu ◽

Cong Zhang ◽

Paul J. Marchand ◽

...

Keyword(s):

Magnetic Field ◽

Statistical Power ◽

Barrel Cortex ◽

Signal Loss ◽

Nuclear Spins ◽

Directional Diffusion ◽

Ischemic Tissue ◽

Significant Difference ◽

Before And After ◽

Experimental Validations

AbstractRecent studies suggested that cerebrovascular micro-occlusions, i.e. microstokes, could lead to ischemic tissue infarctions and cognitive deficits. Due to their small size, identifying measurable biomarkers of these microvascular lesions remains a major challenge. This work aims to simulate potential MRI signatures combining arterial spin labeling (ASL) and multi-directional diffusion-weighted imaging (DWI). Driving our hypothesis are recent observations demonstrating a radial reorientation of microvasculature around the micro-infarction locus during recovery in mice. Synthetic capillary beds, randomly- and radially-oriented, and optical coherence tomography (OCT) angiograms, acquired in the barrel cortex of mice (n = 5) before and after inducing targeted photothrombosis, were analyzed. Computational vascular graphs combined with a 3D Monte-Carlo simulator were used to characterize the magnetic resonance (MR) response, encompassing the effects of magnetic field perturbations caused by deoxyhemoglobin, and the advection and diffusion of the nuclear spins. We quantified the minimal intravoxel signal loss ratio when applying multiple gradient directions, at varying sequence parameters with and without ASL. With ASL, our results demonstrate a significant difference (p < 0.05) between the signal-ratios computed at baseline and 3 weeks after photothrombosis. The statistical power further increased (p < 0.005) using angiograms measured at week 4. Without ASL, no reliable signal change was found. We found that higher ratios, and accordingly improved significance, were achieved at lower magnetic field strengths (e.g., B0 = 3T) and shorter echo time TE (< 16 ms). Our simulations suggest that microstrokes might be characterized through ASL-DWI sequence, providing necessary insights for posterior experimental validations, and ultimately, future translational trials.

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