scholarly journals Magnetic field-induced enhancement of the nitrogen-vacancy fluorescence quantum yield

Nanoscale ◽  
2017 ◽  
Vol 9 (27) ◽  
pp. 9299-9304 ◽  
Author(s):  
M. Capelli ◽  
P. Reineck ◽  
D. W. M. Lau ◽  
A. Orth ◽  
J. Jeske ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Yield ◽  
Magnetic Fields ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Emission ◽  
Excitation Power ◽  
Nitrogen Vacancy ◽  
High Magnetic Fields

The nitrogen-vacancy (NV) centre in diamond is a remarkable optical defect with broad applications. We demonstrate that its fluorescence emission is enhanced at high magnetic fields with low excitation power.

THE STUDY OF THE MAGNETIC BREAKDOWN EFFECT AS A FUNCTION OF ANGLE IN THE ORGANIC CONDUCTOR K- (BEDT-TTF)2Cu(NCS)2 IN HIGH MAGNETIC FIELDS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3355-3359
Author(s):  
I. MIHUT ◽  
C. C. AGOSTA ◽  
C. H. MIELKE ◽  
M. TOKOMOTO
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spin Splitting ◽  
High Magnetic Fields ◽  
Organic Conductor ◽  
Cross Sectional ◽  
Tank Circuit ◽  
Quantum Oscillations ◽  
Magnetic Breakdown ◽  
Splitting Factor

The magnetic breakdown effect can be seen by the growth of new frequencies in the quantum oscillations in clean metals as a function of magnetic field. We have studied the variation of the amplitudes in the quantum oscillations in the resistance (the Shubnikov-de Haas effect) as a function of angle in the quasi-two dimensional-organic conductor κ-(BEDT-TTF)2Cu(NCS)2. The measurements were made by means of a radio frequency (rf) tank circuit (~ 50 MHz) at very high magnetic fields(50T-60T) and low temperature(500 mK). The geometry of the rf excitation we used excited in-plane currents, and therefore we measured the in-plane resistivity. In contrast to conventional transport measurements that measure the inter-plane resistivity, the in-plane resistivity is dominated by the magnetic breakdown frequencies. As a result we measured much higher breakdown frequency amplitudes than conventional transport experiments. As is expected, the angular dependence of the Shubnikov-de Haas frequencies have a 1/cosθ behavior. This is due to the change of the cross sectional area of the tubular Fermi surface as the angle with respect to the magnetic field is changed. The amplitude of the oscillations changes due to the spin splitting factor which takes into account the ratio between the spin splitting and the energy spacing of the Landau levels which also has 1/cosθ behavior. We show that our data agree with the semi-classical theory (Lifshitz-Kosevich formula).

Magnetic Field Effect on Electrochemiluminescence of Carbazole

1971 ◽  
Vol 49 (21) ◽  
pp. 3577-3578 ◽  
Author(s):  
K. S. V. Santhanam
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Emission Intensity ◽  
Applied Field ◽  
Field Effect ◽  
Magnetic Field Effect ◽  
High Magnetic Fields ◽  
Annihilation Rate ◽  
Triplet Triplet Annihilation

Effect of magnetic field on electrochemiluminescence of carbazole has been studied in N,N dimethylformamide. The emission intensity increases with increasing applied field with a tendency to decrease at high magnetic fields. An explanation involving perturbation of triplet–triplet annihilation rate is proposed.

Large volume liquid state scalar Overhauser dynamic nuclear polarization at high magnetic field

2019 ◽  
Vol 21 (38) ◽  
pp. 21200-21204 ◽  
Author(s):  
Thierry Dubroca ◽  
Sungsool Wi ◽  
Johan van Tol ◽  
Lucio Frydman ◽  
Stephen Hill
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
High Magnetic Field ◽  
Dynamic Nuclear Polarization ◽  
Large Volume ◽  
Liquid State ◽  
Nuclear Polarization ◽  
High Magnetic Fields

Dynamic Nuclear Polarization (DNP) can increase the sensitivity of Nuclear Magnetic Resonance (NMR), but it is challenging in the liquid state at high magnetic fields.

Small, modular and economically attractive fusion enabled by high temperature superconductors

2019 ◽  
Vol 377 (2141) ◽  
pp. 20180354 ◽  
Author(s):  
Dennis Whyte
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Magnetic Fields ◽  
Current Density ◽  
High Temperature Superconductors ◽  
Fusion Energy ◽  
High Magnetic Fields ◽  
Operating Temperatures ◽  
The Magnetic Field ◽  
Game Changer

The advantages of high magnetic fields in tokamaks are reviewed, and why they are important in leading to more compact tokamaks. A brief explanation is given of what limits the magnetic field in a tokamak, and why high temperature superconductors (HTSs) are a game changer, not just because of their higher magnetic fields but also for reasons of higher current density and higher operating temperatures. An accelerated pathway to fusion energy is described, defined by the SPARC and ARC tokamak designs. This article is part of a discussion meeting issue ‘Fusion energy using tokamaks: can development be accelerated?’.

Investigation of a novel triazatetrabenzcorrole photosensitizer

2002 ◽  
Vol 06 (07) ◽  
pp. 484-488 ◽  
Author(s):  
Zhenglin Song ◽  
Fushi Zhang ◽  
Xue Li ◽  
Shek-Kiu Chan ◽  
Fuqun Zhao ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Sulfo Groups

A novel phthalocyanine-like photosensitizer, oxophosphorus(V) tetrasulfotriaza-tetrabenzcorrole ( POTBCS 4), has been synthesized. Its structure and absorption spectrum are unique. POTBCS 4 has an axial P = O group and peripheral sulfo groups. The fluorescence emission spectra, fluorescence quantum yield and quantum yield of singlet oxygen generation have been studied. The uptake and the photodynamic activities against HeLa cells were measured. The results indicated that POTBCS 4 was a potential photosensitizer for photodynamic therapy (PDT).

scholarly journals Restoration of superconductivity in high magnetic fields in UTe2

2020 ◽  
Vol 34 (32) ◽  
pp. 2030007
Author(s):  
Andrei G. Lebed
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Superconducting State ◽  
Critical Magnetic Field ◽  
High Magnetic Fields ◽  
Two Dimensional ◽  
Upper Critical Magnetic Field ◽  
Reentrant Superconductivity ◽  
Theoretical Results ◽  
General Method

It was theoretically predicted more than 20 years ago [A. G. Lebed and K. Yamaji, Phys. Rev. Lett. 80, 2697 (1998)], that a triplet quasi-two-dimensional (Q2D) superconductor could restore its superconducting state in parallel magnetic fields, which are higher than its upper critical magnetic field, [Formula: see text]. It is very likely that, recently, such phenomenon has been experimentally discovered in the Q2D superconductor UTe2 by Nicholas Butch, Sheng Ran, and their colleagues and has been confirmed by Japanese–French team. We review our previous theoretical results using such a general method that it describes the reentrant superconductivity in the abovementioned compound and will hopefully describes the similar phenomena, which can be discovered in other Q2D superconductors.

Crystallographic orientation of primary and eutectic phases in a hypoeutectic Mn–Sb alloy induced by solidification in high magnetic fields

2019 ◽  
Vol 52 (5) ◽  
pp. 945-950 ◽  
Author(s):  
Shulin Dong ◽  
Tie Liu ◽  
Meng Dong ◽  
Shuang Wang ◽  
Wen Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Crystallographic Orientation ◽  
Field Direction ◽  
High Magnetic Fields ◽  
Magnetic Field Direction ◽  
Eutectic Alloys ◽  
Random Orientation ◽  
Binary Eutectic ◽  
The Magnetic Field

This paper investigates how applying high magnetic fields influences the crystallographic orientations of the primary and eutectic phases, and their relationship, in a binary eutectic alloy. At 0 T, the primary MnSb phase in hypoeutectic Mn–Sb showed a random orientation, but at 3, 6, 9 and 11.5 T, its c axis was perpendicular to the magnetic field direction. In all cases, the eutectic MnSb phases showed the same orientations as their neighboring primary MnSb phase, on which they nucleated and grew. With high magnetic fields, the c axes of the eutectic and primary MnSb phases were oriented perpendicular to the magnetic field direction. The results show that applying a high magnetic field during solidification is a way of controlling the crystallographic orientation of both the primary and the eutectic phases in eutectic alloys.

TUNING OF THE MAGNETIC FIELD INDUCED SHARP BAND-EDGE OPTICAL ABSORPTION IN EUROPIUM CHALCOGENIDES

2004 ◽  
Vol 18 (27n29) ◽  
pp. 3813-3816 ◽  
Author(s):  
A. B. HENRIQUES ◽  
L. K. HANAMOTO ◽  
E. TER HAAR ◽  
E. ABRAMOF ◽  
A. Y. UETA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Optical Absorption ◽  
Low Temperatures ◽  
Optical Transition ◽  
Band Edge ◽  
Near Band Edge ◽  
High Magnetic Fields ◽  
Sharp Band ◽  
The Magnetic Field

The near band-edge polarized optical optical absortion spectra of EuTe at low temperatures and high magnetic fields were investigated. The samples were grown by MBE on BaF 2 substrates, and the thickness varied in the 0.18-2.0 μm range. At high magnetic fields, the well-known 4f7→4f65d(t2g) optical transition splits into two well resolved lines at σ+ and two lines for σ-. These lines can be described by localized transitions tunable by the d-f exchange interaction, with a quadratic dependence on the intensity of the external magnetic field. Comparative measurements of the magnetization and the optical absorption as a function temperature provides a further test of the model of a localized excitation extending over a few lattice sites.

HIGH-FIELD TRANSPORT PROPERTIES OF T'-Ln2-xCexCuO4 (Ln=Nd, Pr, La)

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3216-3219 ◽  
Author(s):  
T. SEKITANI ◽  
N. MIURA ◽  
M. NAITO
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Magnetic Fields ◽  
Transport Properties ◽  
Normal State ◽  
Low Temperatures ◽  
High Field ◽  
Magnetic Moments ◽  
Negative Magnetoresistance ◽  
High Magnetic Fields

We report low-temperature magnetotransport in the normal state of the electron-doped superconductors, Nd 2-x Ce x CuO 4, Pr 2-x Ce x CuO 4, and La 2-x Ce x CuO 4, by suppressing the superconductivity with high magnetic fields. The normal state ρ-T curve shows an up-turn at low temperatures, which has a log T dependence with saturation at lowest temperatures. The up-turn is gradually suppressed with increasing magnetic field, resulting in negative magnetoresistance. We discuss these findings on the basis of the Kondo scattering originating from the magnetic moments of Cu 2+ ions.

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