Heating of Electrons in Pure Ge in a Quantum Magnetic Field Upon the Thermal Excitation of Charge Carriers

2020 ◽  
Vol 54 (3) ◽  
pp. 275-277
Author(s):  
V. F. Bannaya ◽  
E. V. Nikitina
Keyword(s):  
Magnetic Field ◽  
Charge Carriers ◽  
Thermal Excitation

scholarly journals Разогрев электронов в чистом Ge в квантовом магнитном поле при термическом возбуждении носителей заряда

2020 ◽  
Vol 54 (3) ◽  
pp. 221
Author(s):  
В.Ф. Банная ◽  
Е.В. Никитина
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Electric Field ◽  
Low Temperatures ◽  
Qualitative Agreement ◽  
Carrier Lifetime ◽  
Charge Carriers ◽  
Thermal Excitation ◽  
Ionization Coefficient ◽  
Electric And Magnetic Fields

The results of an experimental study on charge carriers heating by an electric field (E) in pure Ge in a quantum magnetic field (H) at (E⊥H) at low temperatures (T=4,2;1,8 K) under thermal excitation are considered. It is shown that the dependence of E and H thermal ionization coefficient affects the average carrier lifetime under these conditions. The obtained results are in qualitative agreement with the theory of cascade capture of carriers on isolated centers in crossed electric and magnetic fields.

scholarly journals Optothermotronic effect as an ultrasensitive thermal sensing technology for solid-state electronics

2020 ◽  
Vol 6 (22) ◽  
pp. eaay2671 ◽  
Author(s):  
T. Dinh ◽  
T. Nguyen ◽  
A. R. M. Foisal ◽  
H.-P. Phan ◽  
T.-K. Nguyen ◽  
...  
Keyword(s):  
Solid State ◽  
High Performance ◽  
Charge Carriers ◽  
Thermal Excitation ◽  
Light Illumination ◽  
Solid State Electronics ◽  
Sensing Applications ◽  
Sensing Technology ◽  
Thermal Sensing ◽  
Sensing Performance

The thermal excitation, regulation, and detection of charge carriers in solid-state electronics have attracted great attention toward high-performance sensing applications but still face major challenges. Manipulating thermal excitation and transport of charge carriers in nanoheterostructures, we report a giant temperature sensing effect in semiconductor nanofilms via optoelectronic coupling, termed optothermotronics. A gradient of charge carriers in the nanofilms under nonuniform light illumination is coupled with an electric tuning current to enhance the performance of the thermal sensing effect. As a proof of concept, we used silicon carbide (SiC) nanofilms that form nanoheterostructures on silicon (Si). The sensing performance based on the thermal excitation of charge carriers in SiC is enhanced by at least 100 times through photon excitation, with a giant temperature coefficient of resistance (TCR) of up to −50%/K. Our findings could be used to substantially enhance the thermal sensing performance of solid-state electronics beyond the present sensing technologies.

PREFORMED HOLE-PAIRS IN CUPRATE SUPERCONDUCTORS

2009 ◽  
Vol 23 (01) ◽  
pp. 53-76 ◽  
Author(s):  
R. J. SINGH
Keyword(s):  
Magnetic Field ◽  
Cuprate Superconductors ◽  
Charge Carriers ◽  
Nuclear Spins ◽  
Paramagnetic Resonance ◽  
Special Cases ◽  
Hyperfine Splittings ◽  
Single Formula ◽  
Electron Paramagnetic ◽  
Cu Ions

This paper consists of two parts: (1) mechanism of formation of hole-pairs and quantum stripes in cuprate superconductors, and (2) resistivity versus temperature variation in YBa 2 Cu 3 O 7-δ superconductor with different doping levels in the range 400–Tc. (1) On deoxygenation, CuO 2 plane of high-temperature cuprate superconductors are broken into small magnetically isolated fragments, predominantly Cu -tetramer (CuO) 4. Its electron paramagnetic resonance spectra show fine and hyperfine splittings. It was concluded that these splittings are due to FM coupling of the electronic spins of the four holes on the four Cu -ions in (CuO) 4 as well as the FM coupling of the nuclear spins of the four Cu -ions. A magnetic field is generated perpendicular to CuO 2 plane due to the spin magnetic moment of four holes and their orbiting around the (CuO) 4 frame. In the nondeoxygenated superconductors, this magnetic field leads to the formation of quantum stripes of free charge carriers and in special cases to the formation of preformed hole-pairs. This is the first model of a hole-pair, though its existence has been conjectured from various experimental results. (2) The electrical conduction in superconductors along c-axis seems to arise from the movement of free holes and along a-axis from the parallel combination of resistivities arising from the movement of free holes and paired holes, but no single formula connecting ρ and T is applicable to explain resistivities either along c- or a-axis in the entire temperature range. Nature of charge carriers seems to change continuously as the temperature is lowered. In the range 200–Tc, both along the c- and a-axes, the experimental resistivities depart significantly from those calculated by the formula applicable in the range 400–200 K. Plausible explanation has been suggested for the departure of experimental resistivities from the calculated ones in the low temperature region.

The effect of nonlocal conductivity on the transmission of microwave radiation through ferromagnetic metals in the field-normal configuration

1986 ◽  
Vol 64 (7) ◽  
pp. 796-821 ◽  
Author(s):  
K. B. Urquhart ◽  
J. F. Cochran
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Microwave Radiation ◽  
Mean Free Path ◽  
Skin Depth ◽  
Charge Carriers ◽  
Surface Scattering ◽  
Field Distributions ◽  
Wide Range ◽  
Diffuse Surface

Procedures are described for the numerical calculation of the electric-field distributions generated in a model ferromagnetic metal slab of thickness d by incident microwave radiation when a static magnetic field is directed along the slab normal and the mean free path ℓ of the charge carriers becomes comparable to, or greater than, the skin depth δ. The model metal is characterized by a local, frequency-dependent permeability; a spherical Fermi surface; and a nonlocal relationship between the current density and the electric-field distribution. The two limiting cases of specular and diffuse scattering of the charge carriers at the slab faces are considered. Electric-field distributions, transmission amplitudes, and surface impedances have been calculated for a wide range of ℓ and d using parameters that simulate nickel. For diffuse surface scattering, the transmission of the magnetically active mode increases at both ferromagnetic resonance (FMR) and cyclotron resonance (CR). A most striking result is the total absence of structure in the magnetic-field dependence of the transmission amplitude near fields corresponding to FMR or to CR for the case of specular scattering. It is demonstrated that very simple formulae provide a good estimate of the free-space transmission amplitudes for both specular and diffuse surface scattering when [Formula: see text] and d/ℓ ≥ 1.

scholarly journals FREQUENCY TRANSDUCER OF MAGNETIC FIELD INDUCTION BASED ON HETEROMETALLIC COMPLEX COMPOUND

2020 ◽  
pp. 56-64
Author(s):  
O. V. Osadchuk ◽  
V. V. Martyniuk ◽  
M. V. Evseeva ◽  
I. O. Osadchuk
Keyword(s):  
Magnetic Field ◽  
Complex Compound ◽  
Output Signal ◽  
Field Effect Transistors ◽  
Charge Carriers ◽  
Nanocomposite Material ◽  
Heterometallic Complex ◽  
Frequency Transducer ◽  
Increasing Temperature ◽  
Ir Spectroscopic

The possibilities of using nanocomposite material µ-methoxo (copper (II), bismuth (III)) acetylacetonate (I), the following composition: Cu3Bi(AA)4(OCH3)5, де HAA = H3C–C(O)–CH2–C(O)–CH3, as a magnetoresistive sensitive element, in a frequency transducer of a magnetic field. In order to create a suitable heterometallic complex compound, a method for its synthesis was developed. The structure, composition and physicochemical properties of the synthesized nanocomposite material were confirmed on the basis of elemental, X-ray phase analyzes, magnetochemical, IR spectroscopic and thermogravimetric studies. According to research, the density of the corresponding material 𝜌=5,659⋅103 g/m3, the mass of one molecule 𝑚0 = 157,837⋅10−26 kg, the number of valence electrons 𝑁=1450,715⋅1019, which made it possible to calculate the concentration of charge carriers at a temperature of 323 K: 𝑛=82.1⋅1028 m−3. The study of the electrical properties of µ-methoxo (copper (II), bismuth (III)) acetylacetonate in compressed form in the temperature range 323 - 393 K showed that with increasing temperature, its resistivity drops sharply from 8·107 to 70 Ohm·cm, which is typical for semiconductor materials. Based on these data, the band gap 𝛥𝛦 = 2.18 eV was determined. Calculations have shown that this material is a semiconductor, with current carriers of both signs. The dependence of the concentration of charge carriers on the temperature is obtained. The model of the frequency transducer, on the basis of the autogenerator from bipolar to field-effect transistors is considered. Simulation of this scheme was performed in the program LTspice XVIII. Based on this model, the I – V characteristics of this transducer, the dependence of the current, voltage and frequency of the output signal when changing the resistance of the magnetically sensitive resistor. The graph of dependence of frequency of an output signal on induction of a magnetic field on the basis of which sensitivity of the given transducer is defined is received

Band structure for relativistic charge carriers submitted to a helical magnetic field

2021 ◽  
pp. 2150141
Author(s):  
D. Martínez ◽  
J. A. Reyes ◽  
G. Reyes ◽  
C. G. Avendaño
Keyword(s):  
Magnetic Field ◽  
Band Structure ◽  
Charge Carriers ◽  
Momentum Operator ◽  
Rotating Magnetic Field ◽  
Band Gaps ◽  
Spatial Period ◽  
System Parameters ◽  
Helical Magnetic Field ◽  
The Magnetic Field

In this paper, we consider a clockwise rotating magnetic field around the [Formula: see text]-axis and charge carriers which impinge normally to the [Formula: see text] plane. We obtained analytically the spectrum of the momentum operator [Formula: see text] and found the existence of a band structure from which the movement of these charge carries is filtered according to the spatial period of the magnetic field or its intensity. Also we exhibit the existence of three band gaps (one total or primary and two partials) whose width depends on the system parameters.

Out-of-Plane and in-Plane Conduction in Insulating and Strongly Underdoped Cuprates

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3203-3206
Author(s):  
C. C. Almasan ◽  
G. A. Levin ◽  
E. Cimpoiasu ◽  
T. Stein ◽  
D. A. Gajewski ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Normal State ◽  
Low Temperatures ◽  
Elementary Step ◽  
Charge Carriers ◽  
Two Dimensional ◽  
Out Of Plane ◽  
Underdoped Cuprates

We report measurements of out-of-plane (ρ c ) and in-plane (ρab) normal-state resistivities of single crystals of insulating PrBa2Cu3O 7-δ and strongly underdoped oxygen deficient YBa2Cu3O 6.41 using a flux transformer method. In the superconducting specimens, the onset of superconductivity was suppressed by a magnetic field of 9 T. We have found that the anisotropy ρc/ρab of these samples increases monotonically at low temperatures with no signs of saturation. The temperature dependence of ρc/ρab for YBa2Cu3O6.41 is well described by ρc/ρab=a +bT-2/3, but over a smaller temperature range than for insulating PrBa2Cu3O 7-δ. Both the absence of saturation of ρc/ρab and its T-2/3 dependence indicate two-dimensional conduction. This means that the average in-plane hopping distance of the localized charge carriers increases with decreasing T according to Mott's [Formula: see text] law, while the elementary step in the c-direction remains T independent, equal to the spacing between the bilayers.

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