scholarly journals Field-induced quantum breakdown of superconductivity in magnesium diboride

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Soon-Gil Jung ◽  
Jung Min Lee ◽  
Tae-Ho Park ◽  
Tian Le ◽  
Xin Lu ◽  
...  
Keyword(s):  
Magnesium Diboride ◽  
Ion Irradiation ◽  
Percolation Model ◽  
Quantum Phase ◽  
Resistive State ◽  
Iron Ion ◽  
Electron Pairs ◽  
Practical Applications ◽  
Quantum Percolation ◽  
Different Thickness

AbstractThe quantum breakdown of superconductivity (QBS) is the reverse, comprehensive approach to the appearance of superconductivity. A quantum phase transition from superconducting to insulating states tuned by using nonthermal parameters is of fundamental importance to understanding the superconducting (SC) phase but also to practical applications of SC materials. However, the mechanism of the transition to a nonzero resistive state deep in the SC state is still under debate. Here, we report a systematic study of MgB2 bilayers with different thickness ratios for undamaged and damaged layers fabricated by low-energy iron-ion irradiation. The field-induced QBS is discovered at a critical field of 3.2 Tesla (=Hc), where the quantum percolation model best explains the scaling of the magnetoresistance near Hc. As the thickness of the undamaged layer is increased, strikingly, superconductivity is recovered from the insulating state associated with the QBS, showing that destruction of quantum phase coherence among Cooper electron pairs is the origin of the QBS.

QUANTUM PERCOLATION

1995 ◽  
Vol 09 (23) ◽  
pp. 2989-3024 ◽  
Author(s):  
ABHIJIT MOOKERJEE ◽  
INDRA DASGUPTA ◽  
TANUSRI SAHA
Keyword(s):  
Low Temperatures ◽  
Two Dimensions ◽  
Percolation Model ◽  
Quantum Percolation ◽  
Resonant States

In this review we describe and analyze various numerical attempts at understanding transport in the Quantum Percolation Model. We conclude that in two-dimensions all states are localized, though not necessarily exponentially localized, and that transport at low temperatures is dominated by probabilistically exceptional necklace-like resonant states.

scholarly journals Protective Effects of p53 Regulatory Agents Against High-LET Radiation-Induced Injury in Mice

2020 ◽  
Vol 8 ◽  
Author(s):  
Akinori Morita ◽  
Bing Wang ◽  
Kaoru Tanaka ◽  
Takanori Katsube ◽  
Masahiro Murakami ◽  
...  
Keyword(s):  
Cell Death ◽  
Radiation Injury ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Protective Effects ◽  
Iron Ion ◽  
Normal Tissues ◽  
High Let Radiation ◽  
High Let ◽  
Radiation Induced

Radiation damage to normal tissues is one of the most serious concerns in radiation therapy, and the tolerance dose of the normal tissues limits the therapeutic dose to the patients. p53 is well known as a transcription factor closely associated with radiation-induced cell death. We recently demonstrated the protective effects of several p53 regulatory agents against low-LET X- or γ-ray-induced damage. Although it was reported that high-LET heavy ion radiation (>85 keV/μm) could cause p53-independent cell death in some cancer cell lines, whether there is any radioprotective effect of the p53 regulatory agents against the high-LET radiation injury in vivo is still unclear. In the present study, we verified the efficacy of these agents on bone marrow and intestinal damages induced by high-LET heavy-ion irradiation in mice. We used a carbon-beam (14 keV/μm) that was shown to induce a p53-dependent effect and an iron-beam (189 keV/μm) that was shown to induce a p53-independent effect in a previous study. Vanadate significantly improved 60-day survival rate in mice treated with total-body carbon-ion (p < 0.0001) or iron-ion (p < 0.05) irradiation, indicating its effective protection of the hematopoietic system from radiation injury after high-LET irradiation over 85 keV/μm. 5CHQ also significantly increased the survival rate after abdominal carbon-ion (p < 0.02), but not iron-ion irradiation, suggesting the moderate relief of the intestinal damage. These results demonstrated the effectiveness of p53 regulators on acute radiation syndrome induced by high-LET radiation.

Iron ion irradiated Bi2Te3 nanosheets with defects and regulated hydrophilicity to enhance the hydrogen evolution reaction

Nanoscale ◽  
2020 ◽  
Vol 12 (30) ◽  
pp. 16208-16214 ◽  
Author(s):  
Qingtao Wang ◽  
Kai Cui ◽  
Jian Li ◽  
Yanxia Wu ◽  
Yaoxia Yang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Ion Irradiation ◽  
Iron Ion

Introducing defects on the surface of Bi2Te3 by iron ion irradiation can increase active sites, which, in turn, can improve the electrocatalytic HER performance of Bi2Te3 nanosheets.

scholarly journals Evaluation of the toxicity of iron-ion irradiation in murine bone marrow dendritic cells via increasing the expression of indoleamine 2,3-dioxygenase 1

2017 ◽  
Vol 6 (6) ◽  
pp. 958-968 ◽  
Author(s):  
Yi Xie ◽  
Jun-Fang Yan ◽  
Jing-Yi Ma ◽  
Hong-Yan Li ◽  
Yan-Cheng Ye ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Ion Irradiation ◽  
Iron Ion ◽  
Murine Bone Marrow ◽  
Indoleamine 2,3 Dioxygenase

Elevated JNK and IDO1 induced by Fe ion IR could result in dysfunction of BMDCs.

QUANTUM PERCOLATION AND CHARGE TRANSPORT IN HIGH Tc SUPERCONDUCTORS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 3012-3019
Author(s):  
V. DALLACASA ◽  
P. DI SIA
Keyword(s):  
Charge Transport ◽  
Transport Properties ◽  
Interpolation Formula ◽  
Percolation Model ◽  
High Tc Superconductors ◽  
Metal Insulator ◽  
High Tc ◽  
Coulomb Gap ◽  
Quantum Percolation ◽  
Localised States

We have investigated the consequences of internal fields on transport properties in insulators close to a metal-insulator-superconductor transition. An interpolation formula for the resistivity as a function of temperature describing insulating, metallic and superconducting regimes has been deduced in the framework of a quantum percolation model in which hopping processes on localised states occur. The contribution to the internal fields on carriers has been taken into account up to quadrupole terms. The resistivity follows a law ρ ∪(T0)δ T e(T0/T)1/2 where T0 corresponds to a coulomb gap and exhibits anisotropic quadrupole angular dependence, suggesting a correlation with the pseudo-gap observed in superconductors in the underdoped regime.

Deuterium permeation behavior and its iron-ion irradiation effect in yttrium oxide coating deposited by magnetron sputtering

2018 ◽  
Vol 511 ◽  
pp. 560-566 ◽  
Author(s):  
Takumi Chikada ◽  
Hikari Fujita ◽  
Jan Engels ◽  
Anne Houben ◽  
Jumpei Mochizuki ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Yttrium Oxide ◽  
Ion Irradiation ◽  
Oxide Coating ◽  
Irradiation Effect ◽  
Iron Ion
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