Manifestation in IR-Luminescence of Cross Relaxation Processes between NV-Centers in Weak Magnetic Fields

Author(s):  
D. S. Filimonenko ◽  
V. M. Yasinskii ◽  
A. P. Nizovtsev ◽  
S. Ya. Kilin ◽  
F. Jelezko
2021 ◽  
Vol 88 (6) ◽  
pp. 858-871
Author(s):  
D. S. Filimonenko ◽  
V. M. Yasinskii ◽  
A. P. Nizovtsev ◽  
S. Ya. Kilin ◽  
F. Jelezko

We present a combined experimental and theoretical study of the effect of magnetic field on the luminescence from an ensemble of NV centers in diamond. It was found that the intensity of infrared luminescence associated with transitions between singlet levels of NV centers shows a pronounced increase of a near-zero magnetic field. The influence of the power and polarization of laser radiation on the amplitude and shape of the revealed local maximum in IR-luminescence of NV centers is investigated. An eight-level photophysical model of an NV center in the presence of an arbitrarily directed magnetic field has been constructed and on its basis the calculation has been performed of the luminescence intensity emitted by an ensemble of NV center, both in the visible and infrared regions of the spectrum. It is shown that the phenomenological allowance for the cross-relaxation of NV centers between each other and with other paramagnetic centers in a diamond within the framework of this model allows describing the experimentally observed fluorescence features of an ensemble of NV centers in the presence of weak magnetic fields.


2001 ◽  
Vol 56 (9-10) ◽  
pp. 831-837 ◽  
Author(s):  
Alexander Pazur

AbstractBiological effects of weak magnetic fields are widespread, but poorly understood. Besides magnetic particles, which have been shown to be involved in only few cases, membranes are discussed as the site of perception. However, the mechanism is unknown. We have subjected pure lipid membranes to weak magnetic pulses, and found, that their electric properties are modified.Black lipid membranes were prepared from purified asolectin on a teflon septum separating electrically the two chambers of a teflon cuvette, using the technique of Mueller et al. (1962). Single magnetic pulses were applied for 10 μs, whose intensity could be varied from 0 to 100 G (0 to 10 mT) at the membrane. Directly after the pulse decay, the conductance of the bilayers was scanned with 10 periods of a 1 kHz triangle alternating voltage (eg. a measurement time window of 10 ms). Frequency spectra of the bilayer current rose by a frequency dependent factor ≤ 2 in a broad region around 80 kHz, when the amplitude of the preceding magnetic pulse was increased from 0 to 100 G. The data show, that weak magnetic fields can significantly change the electrical conductance of lipid films. The relaxation of electrons in a two-dimensional quantum state (“quantum hollow”) will be discussed as a possible origin of these effects.


2019 ◽  
Author(s):  
Valentina Guccini ◽  
Sugam Kumar ◽  
Yulia Trushkina ◽  
Gergely Nagy ◽  
Christina Schütz ◽  
...  

The magnetic alignment of cellulose nanocrystals (CNC) and lepidocrocite nanorods (LpN), pristine and in hybrid suspensions has been investigated using contrast-matched small-angle neutron scattering (SANS) under in situ magnetic fields (0 – 6.8 T) and polarized optical microscopy. The pristine CNC (diamagnetic) and pristine LpN (paramagnetic) align perpendicular and parallel to the direction of field, respectively. The alignment of both the nanoparticles in their hybrid suspensions depends on the relative amount of the two components (CNC and LpN) and strength of the applied magnetic field. In the presence of 10 wt% LpN and fields < 1.0 T, the CNC align parallel to the field. In the hybrid containing lower amount of LpN (1 wt%), the ordering of CNC is partially frustrated in all range of magnetic field. At the same time, the LpN shows both perpendicular and parallel orientation, in the presence of CNC. This study highlights that the natural perpendicular ordering of CNC can be switched to parallel by weak magnetic fields and the incorporation of paramagnetic nanoparticle as LpN, as well it gives a method to influence the orientation of LpN.<br>


RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17051-17057
Author(s):  
Anna Eichler-Volf ◽  
Yara Alsaadawi ◽  
Fernando Vazquez Luna ◽  
Qaiser Ali Khan ◽  
Simon Stierle ◽  
...  

PS/CoPd Janus particles respond very sensitively to application of low external magnetic fields. Owing to the magnetic properties, the PS/CoPd particles may be used, for example, to sense the presence of weak magnetic fields as micro-magnetometers.


2014 ◽  
Vol 78 (11) ◽  
pp. 1169-1173 ◽  
Author(s):  
N. A. Yudanov ◽  
A. A. Rudyonok ◽  
L. V. Panina ◽  
A. T. Morchenko ◽  
A. V. Kolesnikov ◽  
...  

BIOPHYSICS ◽  
2010 ◽  
Vol 55 (4) ◽  
pp. 652-660 ◽  
Author(s):  
A. V. Drozdov ◽  
T. P. Nagorskaya ◽  
S. V. Masyukevich ◽  
E. S. Gorshkov

1998 ◽  
Vol 95 (1) ◽  
pp. 71-89 ◽  
Author(s):  
C.R. Timmel ◽  
U. Till ◽  
B. Brocklehurst ◽  
K.A. Mclauchlan ◽  
P.J. Hore

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