The Effective Mass Density of States

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New Method of Determining the Landau Levels in Narrow Gap Semiconductors

New Method of Determining the Landau Levels in Narrow Gap Semiconductors

With the help of mathematical models, the temperature dependence of the density of energy states was determined in a quantizing magnetic field. The influence of the effective mass at the temper- ature dependence of the density of the energy states in a strong quantizing magnetic field is inves- tigated. The dependence temperature of density of energy states graph is obtained in a strong magnetic field for InSb.

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The Temperature Dependence of the Density of States in Semiconductors

The Temperature Dependence of the Density of States in Semiconductors

the thermal broadening of the density of states near the bottom of the conduction band, valence band reduces band gap. In the calculation of the temperature depend- ence of the forbidden assumed for simplicity, the density of states in the areas of constant edge of the conduction band and valence band is sharp and has a stepped shape. In these works, the effective mass of the density of states does not depend on the temperature. However, as shown in experiments [9], the effective mass of the density of states depends on the temperature. This change in the effective mass changes the temperature dependence of the band gap. However, in the real state of the semicon- ductor, density is a function of speed and energy band structure of the sample is determined. Moreover, the density of states is so general that it can be used even when there is no Brillouin zone and sharp boundaries of permitted and prohibited zones [10,11].
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Organisation of p-type two dimensional semi-conductor structures for FET applications

Organisation of p-type two dimensional semi-conductor structures for FET applications

L aser emission principally occurs across the F -p o in t Any emission at a higher energy can therefore essentially be considered as the loss of an electron which now will not contribute to the emission process at the wavelength o f interest. One would therefore like to minimise the num ber of states at energies that do not participate in the emission at the particular wavelength. This again involves tailoring the density of states and effective mass. Bandstructure engineering can therefore offer a reduction in threshold current. A lower density of states can be achieved by using for example strained structures [Sin93] or choosing non-conventional growth directions [Bat89,Men92]. The quest for a density of states in which losses via emission at non-relevant wavelengths are minimised also explains the move from 3D laser structures towards 2D, with a push to go to ever lower dimensions [Wei91,Zor93]. At this point, the connection between wavelength, threshold-current and bandstructure has been established. Furthermore, it was shown that the parity of the wavefunctions detemiines whether an optical transition is allowed or forbidden. However, the wavefunctions influence optical transitions in more ways than ju st through parity. Symmetry on atomic scale o f the wavefunctions involved in a transition governs the polarisation of the emitted photons. Wavefunction engineering can be used here to tailor the polarisation to the specific needs. One example is the use of [31 l]-substrates to produce Vertical Cavity SEmiconductor Lasers (VCSELs) that exhibit a clamped polarisation direction [Tat97], in contrast to [ 0 0 1 )-grown equivalents which exhibit random and even bi-stable polarisation
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The Magnetic Field in the Stability  of the Stars

The Magnetic Field in the Stability of the Stars

the distribution of pressure, mass density and temperature are obtained. As work hypothesis, it is considered that at first approximation, the scheme distribution is homologous from star to star. This means that all gaseous stars copy the same stellar model within its appropriate scale of mass, length, temperature, etc. [1]. In order to, once and for all, simplify the task, a general solution to the problem is formulated and then the question is reduced to adapt it to the scale of the particular star being studied. It is important to notice that Eddington abandons J. Homer Lane’s hypothesis [1] [2] when he does not consider that the thermal equilibrium in a gaseous star is due to the existence of internal convective streams. The hypothesis of convective equilibrium is replaced by the ra- diative equilibrium and this last basic principle is applied to the internal conditions of the sun and the stars [1].
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Density Estimation methods based on Mass

Density Estimation methods based on Mass

Density estimation is ubiquitously applied to various taskssuch as clustering, classification, anomaly detection andinformation retrieval. Despite its pervasive use, thereare no efficient density estimation methods thus far. Most existing methods such as kernel density estimator and k-nearest neighbor density estimator cannot be applied toproblems with even a moderate number of dimensions andlarge data size. This paper is motivated to study efficient method for density estimation. The threeexisting density-based algorithms, when employ the density estimator, set a new runtime benchmark that is ordersof magnitude faster.
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Auxetics and other systems of “negative” characteristics

Auxetics and other systems of “negative” characteristics

Tomasz Strek, Hubert Jopek, and Maria Nienartowicz simulate the effective properties and dynamic response of a sandwich panel made of two face-sheets and an auxetic core [24]. They show that it is possible to create auxetic sandwich panels made of two solid materials with positive Poisson's ratio. This is even possible if the filler material is nearly incompressible, but can move in an out-of-plane direction. Moreover, the effective Young's modulus of such sandwich panels becomes very large if the Poisson's ratio of the filler material tends to -1.

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Modification of electronic surface states by graphene islands on Cu(111)

Modification of electronic surface states by graphene islands on Cu(111)

Graphene’s unique electronic and physical properties have fueled investment for a variety of applications. However, as it is only one atom thick, graphene’s interaction with metal electrodes or substrates can have a strong effect on its inherent properties [1]. Copper commands special interest as the most commonly used metal substrate for graphene growth by chemical vapor deposition (CVD) [2]. Copper is also a common contaminant in CVD graphene films transferred to other substrates [3]. The electronic states of the (111) face of single crystal copper provide an additional opportunity to probe interfacial electronic structure due to adlayers. Several recent experiments have taken advantage of these exposed surface states of crystalline metal substrates for such studies [4–7]. On Cu(111), an occupied Shockley surface state forms in the projected band gap leading to a quasi-two-dimensional electron gas [8], which can act as a sensitive probe of changes in the surface electronic potential. Additional unoccupied surface states form due to the potential well created by an electron and its image charge. These image potential states (IPS) occur in a Rydberg series pinned to the vacuum level and thus serve as a local probe of the work function. Studies of Shockley states and IPS can help determine the interaction between adlayers and substrates as well as the resulting charge transfer to the adlayer [1]. Most of these studies have involved either thin dielectric films [7], noble gases [9], few-layer metals [10,11], or self-assembled molecular monolayers [12]. As graphene is a metallic two-dimensional (2D) crystal with weak van der Waals substrate coupling, surface state changes due to a graphene sheet may lead to new understanding of graphene/metal interactions as well as surface state physics. The graphene/metal system also presents an interesting opportunity to study whether a 2D metal that is entirely surface will present its own surface states, as was recently predicted for freestanding graphene [13].
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Density Estimation methods based on Mass

Density Estimation methods based on Mass

where the expectation E[·] is taken over the distribution of ¯fm(x).The result indicates that the variance increases when level h increases. Also, the result does not change even if we use the higher order approximation because the term pd(ci)=vi dominates in the above formula. The property of DEMass, revealed from this error analysis, is similar to that of the conventional kernel density estimator which shows a bias-variance trade off—the bias decreases as the kernel bandwidth b decreases but this increases the variance; and the reverse is true if the kernel bandwidth in increased
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Excitons with anisotropic effective mass

Excitons with anisotropic effective mass

Most semiconductors used for modern electronic de- vices crystallize in the diamond (e.g. Si, Ge), zincblende (e.g. GaAs) or wurtzite (e.g. GaN) structure, for which the constant energy surfaces E( k ) about the valence band maximum and conduction band minimum are ellipsoidal in shape, yielding distinct longitudinal electron and hole effective masses m e

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Effect of fat mass and lean mass on bone mineral density in postmenopausal and perimenopausal Thai women

Effect of fat mass and lean mass on bone mineral density in postmenopausal and perimenopausal Thai women

Background: The purpose of this study was to investigate the association between fat mass, lean mass, and bone mineral density (BMD) in postmenopausal and perimenopausal Thai women. Methods: A cross-sectional study was conducted in 1579 healthy Thai women aged 40–90 years. Total body, lumbar spine, total femur, and femoral neck BMD and body composition were measured by dual x-ray absorptiometry. To evaluate the associations between fat mass and lean mass and various measures of BMD, multivariable linear regression models were used to estimate the regression coefficients for fat mass and lean mass, first in separate equations and then with both fat mass and lean mass in the same equation.
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Aerosol effective density measurement using scanning mobility particle sizer and quartz crystal microbalance with the estimation of involved uncertainty

Aerosol effective density measurement using scanning mobility particle sizer and quartz crystal microbalance with the estimation of involved uncertainty

through two diffusion dryers placed in series. This dried aerosol stream (RH < 5 %) was then introduced to the SMPS (through the inlet impactor). Downstream of the DMA, the aerosol flow was subdivided into two parts. One was con- nected to the CPC and other one to the QCM, which were placed at equal distances from the DMA (the tube length between DMA exit and inlet of CPC or QCM was 25 cm). The sample flow rate of the SMPS was set to 0.48 L min −1 , which is a sum of flow rates of the CPC and the QCM, i.e. 0.24 L min −1 each. The purpose of selecting 0.24 L min −1 for the CPC is to keep its flow rate equal to the flow rate of the QCM (which works only at 0.24 L min −1 for better size segregation). Sheath flow rate of the SMPS was set to 4.8 L min −1 . Particles of size range 10–478 nm were segre- gated by the DMA and number concentration was measured by the CPC. Simultaneously, the corresponding mass distri- bution was obtained from the QCM. For the calculation of effective density, we used count mean diameter (CMD) de- rived from the size distribution scan over a size range 10– 478 nm of the CPC and the real-time corresponding mass concentration obtained from the QCM downstream of the DMA. In this approach, we assumed that particles are spher- ical (χ = 1, Eq. 1), thus the electrical mobility diameter (d m ,
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The high aerobic capacity of a small, marsupial rat kangaroo (Bettongia penicillata) is matched by the mitochondrial and capillary morphology of its skeletal muscles

The high aerobic capacity of a small, marsupial rat kangaroo (Bettongia penicillata) is matched by the mitochondrial and capillary morphology of its skeletal muscles

Both the coefficient and the exponent of Eqn9 are not different from those in Eqn7 [coefficient, t0.015, d.f.21, P>0.50; exponent, t0.080, d.f.20, P>0.50; using the method of Zar (Zar, 1999)]. Conclusively then, we can say that both M. rufus and B. penicillata exhibit V O2,max that are equivalent to those of athletic placental mammals of the comparable sizes. The principal difference between athletic and non-athletic placentals appears to be the expansibility of their aerobic capacity, i.e. in fAS. That of athletic species is markedly higher than that of the non-athletic group (Weibel et al., 2004). As noted above, our macropodiform marsupials had higher fAS values than all placentals, and high fAS values appear to be a general feature for marsupials. Their relatively low BMR are countered by levels of maximal metabolism at least equivalent to those of placental mammals (Dawson and Dawson, 1982). Values for V O2,max for nine marsupial species (mass range 16g to 5kg) (Hinds et al., 1993) are all higher than the V O2,max values predicted from Eqn8 above, i.e. that for non-athletic placentals. The possibility that marsupials other than the Macropodiformes tend to ‘athleticism’ requires investigation.
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Template effect in TiN/AlN multilayered coatings from first principles

Template effect in TiN/AlN multilayered coatings from first principles

To gain further insight into electronic states, we present in Fig. 5 density of states (DOS) projected on selected atomic layers of the relaxed Ti-terminated surface during the adsorption process. From the fig.5(a), it could be seen that the SN and STi layers are first two layers in TiN surface, and the N1, Al2, N3, Al4, N5, and Al6 denote the added layers at corresponding step. The states for the SN layers are similar, implying that the added atoms impose an insignificant influence on the TiN layers. The adsorption of Al2 atom extends greatly the width of states located mainly from −7.5 to 0 eV and reduces the magnitude of the DOS for the neighbouring N1 atom. Consequently, when the N3 atom is added, the N1layer shows similar states as in the N1 case. From partial DOS (PDOS) of all layers, the hybridization between the neighbouring layers takes place not only below E F but within the energy range of 17.5
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A Study of Neutron and Gamma Ray  Interaction Properties with Cobalt Free Highly Chromium Maraging Steel

A Study of Neutron and Gamma Ray Interaction Properties with Cobalt Free Highly Chromium Maraging Steel

The relation between the γ -ray attenuation coefficients and chromium contents is given in Figure 4; the equa- tion for the fitting function and the linear regression coefficient, R 2 , is given in each graph. It is clearly seen from Figure 3 and Figure 4 that, mass attenuation coefficients and removal cross section are inversely propor- tional to the chromium contents. This result shows that there are some sorts of analogy between the fast neutron removal cross section and the γ -ray attenuation coefficients.

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Scaling of morphology and ultrastructure of hearts among wild African antelope

Scaling of morphology and ultrastructure of hearts among wild African antelope

oxygen-supply capacity because it is linked with total capillary blood volume, total capillary endothelial surface area and average oxygen diffusion distance to the mitochondria (Hoppeler and Kayar, 1988; Hoppeler et al., 1981b). Likewise, total mitochondrial inner membrane surface area is a morphometric descriptor of global oxygen-consumption capacity, because it is on the inner membrane that the enzymes of oxidative phosphorylation are embedded and where oxygen ultimately is consumed at the final step of the electron transport chain (Hoppeler and Kayar, 1988; Hoppeler et al., 1981a). It is significant, then, that we find proportionality between these two variables for the heart, implied by the parallel scaling of total capillary length (exponent 0.74±0.16; Fig. 3A) and total mitochondrial inner membrane surface area (exponent 0.78±0.10; Fig. 3B), and demonstrated by their linear covariance (Fig. 4). This proportionality conforms to the economic design principle of symmorphosis, which posits that no more structure should exist in a system, including the steps of the oxygen cascade, than is necessary to satisfy the functional capacity of the system, assuming the driving design feature is the transport of oxygen. The functional aerobic capacity of the heart, a state that is probably approached during heavy aerobic exercise, should be reflected in the global maximum oxygen-consumption rate of the cardiac tissue. Symmorphosis would also predict that the maximum oxygen-consumption rate of the antelope heart should scale in parallel with total capillary length and total mitochondrial inner membrane surface area – that is, with an exponent of ca. 0.74 – 0.78 in a power equation on body mass. We cannot yet test this hypothesis directly because data for the aerobic capacity of cardiac tissue in our antelope are unavailable. Nonetheless, if the scaling of heart mass is associated with stroke
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The Mass Energy Equivalence Principle in Fluid Dynamics

The Mass Energy Equivalence Principle in Fluid Dynamics

H . (38) This is the equation for the energy density of a continuous at rest medium. It expresses the equivalence be- tween energy and mass densities in the field of fluid dynamics. It is clear that as H is the energy per unit vo- lume and ρ o the mass of fluid also per unit volume, Equation (38) reduces to the well known Einstein Equation

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Effective atomic number and electron densities for L Arginine LR at several photon energies

Effective atomic number and electron densities for L Arginine LR at several photon energies

The L Arginine LR samples under investigation were confined in cylindrical plastic containers or inner diameter 2.5 cm. It was found that the attenuation of the photon beam by the material of the empty containers was negligible. Each sample thus prepared was weighed in an electrical balance exactly to the third decimal place. The weighing was repeated a number of times to obtain concordant values of the mass. A mean of this set of concordant values was taken to be the mass of the sample. The inner diameter of each container was determined separately with the help of a traveling microscope by the usual method. Using the mean values of the mass and the inner diameter, the mass per unit area of each sample was determined. The thickness of the samples (mass per unit area) was chosen such that a µt < 0.6 [27] criterion was satisfied at each energy, in order to minimize the effects due to multiple scattering.
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mass density volume

mass density volume

material(s) of variable density, and we wish to compute its mass. One response to such a problem is simply to weigh the object in question, but there are cases in which this is not possible and one needs some indirect method of determining the object’s mass.

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Machiavelli-the_prince_oup ed. bonadella

Machiavelli-the_prince_oup ed. bonadella

Bergamo, Bartolomeo da: (  –  ), Bartolomeo Colleoni, mer- cenary soldier from Bergamo, who served Naples, Florence, Venice, and Milan at various times in his illustrious career. From  until his death he was the commander of Venetian armies and was con- sidered one of the greatest Italian condottieri of the period. Andrea del Verrocchio’s famous equestrian statue of Colleoni stands today in the Campo Santi Giovanni e Paolo in Venice, and is one of the greatest equestrian statues produced during the Italian Renaissance. Borgia, Cesare: (  –  ), son of Cardinal Rodrigo Borgia (later Pope Alexander VI) and Vannozza Catanei. Like his father, Cesare studied canon law in Italy at Perugia and Pisa, became archbishop of Valencia when his father was elected Pope, and was made a car- dinal by his father in  . Pedro Luiz, the son that the Pope had destined for a secular career, died in  , and the Pope’s other son Juan was murdered in  . Cesare therefore renounced his pos- ition as cardinal and received from King Louis XII of France the title of Duke of Valentinois (hence, the name Duke Valentino, by which he was known to Machiavelli and the Italians). Returning to Italy in  , Cesare began to attack a number of rulers in the Papal States as the captain-general of the papal army, capturing Fano, Pesaro, Rimini, Cesena, Faenza, Imola, and Forlì. Named Duke of the Romagna by Alexander, Cesare planned to attack Camerino and Urbino. In  he thwarted a plot by his mercenary allies and executed the ringleaders after tricking them into a meeting at Seni- gallia. When his father fell ill in  , Cesare tried to hold on to power by supporting the election of Julius II. When this move failed he fl ed to Naples, where he was arrested by the Spanish viceroy and returned to Spain and imprisoned; but after escaping he served the
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Locke Second Treatise + MIll

Locke Second Treatise + MIll

compared to others whom we’ll encounter soon. Why do we think this? Because he sees humanity as inevitably leading to that state of war/state of nature and this si why we form societies and states. But he insists on natural equality and freedom as something prior to any social contract or state. Locke, as we will see, follows Hobbes in this—natural equality. With Locke, or after rereading or discussing as needed, you should see our world emerge quite clearly: the world of civil government and the rule of law.

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