scholarly journals How do phonons relax molecular spins?

2019 ◽  
Vol 5 (9) ◽  
pp. eaax7163 ◽  
Author(s):  
Alessandro Lunghi ◽  
Stefano Sanvito
Keyword(s):  
Spin Relaxation ◽  
Hyperfine Coupling ◽  
Spin Dynamics ◽  
Hyperfine Interactions ◽  
Dipolar Interaction ◽  
Relaxation Mechanism ◽  
First Principles Calculations ◽  
Electronic Spin ◽  
Comprehensive Study

The coupling between electronic spins and lattice vibrations is fundamental for driving relaxation in magnetic materials. The debate over the nature of spin-phonon coupling dates back to the 1940s, but the role of spin-spin, spin-orbit, and hyperfine interactions has never been fully established. Here, we present a comprehensive study of the spin dynamics of a crystal of Vanadyl-based molecular qubits by means of first-order perturbation theory and first-principles calculations. We quantitatively determine the role of the Zeeman, hyperfine, and electronic spin dipolar interactions in the direct mechanism of spin relaxation. We show that, in a high magnetic field regime, the modulation of the Zeeman Hamiltonian by the intramolecular components of the acoustic phonons dominates the relaxation mechanism. In low fields, hyperfine coupling takes over, with the role of spin-spin dipolar interaction remaining the less important for the spin relaxation.

Spin Dynamics of Radical Pairs with Restricted Geometries and Strong Exchange Coupling: The Role of Hyperfine Coupling

2014 ◽  
Vol 118 (24) ◽  
pp. 4249-4255 ◽  
Author(s):  
Mehdi Zarea ◽  
Raanan Carmieli ◽  
Mark A. Ratner ◽  
Michael R. Wasielewski
Keyword(s):  
Exchange Coupling ◽  
Hyperfine Coupling ◽  
Spin Dynamics ◽  
Radical Pairs ◽  
Strong Exchange

The Role of the Internet of Things in Health Care: A Systematic and Comprehensive Study

2020 ◽  
Author(s):  
Navod Neranjan Thilakarathne ◽  
Mohan Krishna Kagita ◽  
Thippa Reddy Gadekallu
Keyword(s):  
Health Care ◽  
Internet Of Things ◽  
The Internet ◽  
The Internet Of Things ◽  
Comprehensive Study

Dietary Carotenoids in Managing Metabolic Syndrome and Role of PPARs in the Process

2020 ◽  
Vol 16 (6) ◽  
pp. 846-853
Author(s):  
Raghunandan Purohith ◽  
Nagendra P.M. Nagalingaswamy ◽  
Nanjunda S. Shivananju
Keyword(s):  
Metabolic Syndrome ◽  
Dietary Intervention ◽  
Bioactive Constituents ◽  
Dietary Antioxidants ◽  
Predisposing Factor ◽  
Beneficial Effects ◽  
Pathological Conditions ◽  
Established Relationship ◽  
Comprehensive Study

Metabolic syndrome is a collective term that denotes disorder in metabolism, symptoms of which include hyperglycemia, hyperlipidemia, hypertension, and endothelial dysfunction. Diet is a major predisposing factor in the development of metabolic syndrome, and dietary intervention is necessary for both prevention and management. The bioactive constituents of food play a key role in this process. Micronutrients such as vitamins, carotenoids, amino acids, flavonoids, minerals, and aromatic pigment molecules found in fruits, vegetables, spices, and condiments are known to have beneficial effects in preventing and managing metabolic syndrome. There exists a well-established relationship between oxidative stress and major pathological conditions such as inflammation, metabolic syndrome, and cancer. Consequently, dietary antioxidants are implicated in the remediation of these complications. The mechanism of action and targets of dietary antioxidants as well as their effects on related pathways are being extensively studied and elucidated in recent times. This review attempts a comprehensive study of the role of dietary carotenoids in alleviating metabolic syndromewith an emphasis on molecular mechanism-in the light of recent advances.

scholarly journals A comprehensive study on the role of advanced technologies in 5G based smart hospital

2021 ◽  
Vol 60 (6) ◽  
pp. 5527-5536
Author(s):  
Arun Kumar ◽  
R. Dhanagopal ◽  
Mahmoud A. Albreem ◽  
Dac-Nhuong Le
Keyword(s):  
Advanced Technologies ◽  
Smart Hospital ◽  
Comprehensive Study

Spin dynamics in the organic spin - Peierls system MEM(TCNQ) studied using muon-spin relaxation

1997 ◽  
Vol 9 (9) ◽  
pp. L119-L124 ◽  
Author(s):  
S J Blundell ◽  
F L Pratt ◽  
P A Pattenden ◽  
M Kurmoo ◽  
K H Chow ◽  
...  
Keyword(s):  
Spin Relaxation ◽  
Spin Dynamics ◽  
Muon Spin ◽  
Muon Spin Relaxation

An effective and efficient approach to p-type AlN by Be2:O codoping from first-principles calculations

2016 ◽  
Vol 30 (20) ◽  
pp. 1650257
Author(s):  
Meng Zhao ◽  
Wenjun Wang ◽  
Jun Wang ◽  
Junwei Yang ◽  
Weijie Hu ◽  
...  
Keyword(s):  
First Principles ◽  
Ionization Energy ◽  
Hole Concentration ◽  
Valence Band Maximum ◽  
First Principles Calculations ◽  
Mutual Compensation ◽  
Efficient Approach ◽  
P Type ◽  
Codoping Method

Various Be:O-codoped AlN crystals have been investigated via first-principles calculations to evaluate the role of the different combinations in effectively and efficiently inducing p-type carriers. It is found that the O atom is favored to bond with two Be atoms. The formed Be2:O complexes decrease the acceptor ionization energy to 0.11 eV, which is 0.16 eV lower than that of an isolated Be in AlN, implying that the hole concentration could probably be increased by 2–3 orders of magnitude. The electronic structure of Be2:O-codoped AlN shows that the lower ionization energy can be attributed to the interaction between Be and O. The Be–O complexes, despite failing to induce p-type carriers for the mutual compensation of Be and O, introduce new occupied states on the valence-band maximum (VBM) and hence the energy needed for the transition of electrons to the acceptor level is reduced. Thus, the Be2:O codoping method is expected to be an effective and efficient approach to realizing p-type AlN.

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