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Hermite Polynomial

Hermite polynomials are a set of orthogonal polynomials that arise in probability, combinatorics, and physics, particularly in the context of quantum mechanics and the solution of differential equations. They are defined by the recurrence relation:

Hn(x)=2xHn−1(x)−2(n−1)Hn−2(x)H_n(x) = 2xH_{n-1}(x) - 2(n-1)H_{n-2}(x)Hn​(x)=2xHn−1​(x)−2(n−1)Hn−2​(x)

with the initial conditions H0(x)=1H_0(x) = 1H0​(x)=1 and H1(x)=2xH_1(x) = 2xH1​(x)=2x. The nnn-th Hermite polynomial can also be expressed in terms of the exponential function and is given by:

Hn(x)=(−1)nex2/2dndxne−x2/2H_n(x) = (-1)^n e^{x^2/2} \frac{d^n}{dx^n} e^{-x^2/2}Hn​(x)=(−1)nex2/2dxndn​e−x2/2

These polynomials are orthogonal with respect to the weight function w(x)=e−x2w(x) = e^{-x^2}w(x)=e−x2 on the interval (−∞,∞)(- \infty, \infty)(−∞,∞), meaning that:

∫−∞∞Hm(x)Hn(x)e−x2 dx=0for m≠n\int_{-\infty}^{\infty} H_m(x) H_n(x) e^{-x^2} \, dx = 0 \quad \text{for } m \neq n∫−∞∞​Hm​(x)Hn​(x)e−x2dx=0for m=n

Hermite polynomials play a crucial role in the formulation of the quantum harmonic oscillator and in the study of Gaussian integrals, making them significant in both theoretical and applied

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Nanowire Synthesis Techniques

Nanowires are ultra-thin, nanometer-scale wires that exhibit unique electrical, optical, and mechanical properties, making them essential for various applications in electronics, photonics, and nanotechnology. There are several prominent techniques for synthesizing nanowires, including Chemical Vapor Deposition (CVD), Template-based Synthesis, and Electrospinning.

  1. Chemical Vapor Deposition (CVD): This method involves the chemical reaction of gaseous precursors to form solid materials on a substrate, resulting in the growth of nanowires. The process can be precisely controlled by adjusting temperature, pressure, and gas flow rates.

  2. Template-based Synthesis: In this technique, a template, often made of porous materials like anodic aluminum oxide (AAO), is used to guide the growth of nanowires. The desired material is deposited into the pores of the template, and then the template is removed, leaving behind the nanowires.

  3. Electrospinning: This method utilizes an electric field to draw charged polymer solutions into fine fibers, which can be collected as nanowires. The resulting nanowires can possess various compositions, depending on the precursor materials used.

These techniques enable the production of nanowires with tailored properties for specific applications, paving the way for advancements in nanoscale devices and materials.

Chebyshev Polynomials Applications

Chebyshev polynomials are a sequence of orthogonal polynomials that have numerous applications across various fields such as numerical analysis, approximation theory, and signal processing. They are particularly useful for minimizing the maximum error in polynomial interpolation, making them ideal for constructing approximations of functions. The polynomials, denoted as Tn(x)T_n(x)Tn​(x), can be defined using the relation:

Tn(x)=cos⁡(n⋅arccos⁡(x))T_n(x) = \cos(n \cdot \arccos(x))Tn​(x)=cos(n⋅arccos(x))

for xxx in the interval [−1,1][-1, 1][−1,1]. In addition to their role in interpolation, Chebyshev polynomials are instrumental in filter design and spectral methods for solving differential equations, where they help in achieving better convergence properties. Furthermore, they play a crucial role in the field of computer graphics, particularly in rendering curves and surfaces efficiently. Overall, their unique properties make Chebyshev polynomials a powerful tool in both theoretical and applied mathematics.

Anisotropic Thermal Conductivity

Anisotropic thermal conductivity refers to the directional dependence of a material's ability to conduct heat. Unlike isotropic materials, which have uniform thermal conductivity regardless of the direction of heat flow, anisotropic materials exhibit varying conductivity based on the orientation of the heat gradient. This behavior is particularly important in materials such as composites, crystals, and layered structures, where microstructural features can significantly influence thermal performance.

For example, the thermal conductivity kkk of an anisotropic material can be described using a tensor, which allows for different values of kkk along different axes. The relationship can be expressed as:

q=−k∇T\mathbf{q} = -\mathbf{k} \nabla Tq=−k∇T

where q\mathbf{q}q is the heat flux, k\mathbf{k}k is the thermal conductivity tensor, and ∇T\nabla T∇T is the temperature gradient. Understanding anisotropic thermal conductivity is crucial in applications such as electronics, where heat dissipation is vital for performance and reliability, and in materials science for the development of advanced materials with tailored thermal properties.

Riemann Zeta Function

The Riemann Zeta Function is a complex function defined for complex numbers sss with a real part greater than 1, given by the series:

ζ(s)=∑n=1∞1ns\zeta(s) = \sum_{n=1}^{\infty} \frac{1}{n^s}ζ(s)=n=1∑∞​ns1​

This function has profound implications in number theory, particularly in the distribution of prime numbers. It can be analytically continued to other values of sss (except for s=1s = 1s=1, where it has a simple pole) and is intimately linked to the famous Riemann Hypothesis, which conjectures that all non-trivial zeros of the zeta function lie on the critical line Re(s)=12\text{Re}(s) = \frac{1}{2}Re(s)=21​ in the complex plane. The zeta function also connects various areas of mathematics, including analytic number theory, complex analysis, and mathematical physics, making it one of the most studied functions in mathematics.

Phillips Phase

The Phillips Phase refers to a concept in economics that illustrates the relationship between unemployment and inflation, originally formulated by economist A.W. Phillips in 1958. Phillips observed an inverse relationship, suggesting that lower unemployment rates correlate with higher inflation rates. This relationship is often depicted using the Phillips Curve, which can be expressed mathematically as π=πe−β(u−un)\pi = \pi^e - \beta (u - u_n)π=πe−β(u−un​), where π\piπ is the rate of inflation, πe\pi^eπe is the expected inflation, uuu is the unemployment rate, unu_nun​ is the natural rate of unemployment, and β\betaβ is a positive constant. Over time, however, economists have noted that this relationship may not hold in the long run, particularly during periods of stagflation, where high inflation and high unemployment occur simultaneously. Thus, the Phillips Phase highlights the complexities of economic policy and the need for careful consideration of the trade-offs between inflation and unemployment.

Spin-Orbit Coupling

Spin-Orbit Coupling is a quantum mechanical phenomenon that occurs due to the interaction between a particle's intrinsic spin and its orbital motion. This coupling is particularly significant in systems with relativistic effects and plays a crucial role in the electronic properties of materials, such as in the behavior of electrons in atoms and solids. The strength of the spin-orbit coupling can lead to phenomena like spin splitting, where energy levels are separated according to the spin state of the electron.

Mathematically, the Hamiltonian for spin-orbit coupling can be expressed as:

HSO=ξL⋅SH_{SO} = \xi \mathbf{L} \cdot \mathbf{S}HSO​=ξL⋅S

where ξ\xiξ represents the coupling strength, L\mathbf{L}L is the orbital angular momentum vector, and S\mathbf{S}S is the spin angular momentum vector. This interaction not only affects the electronic band structure but also contributes to various physical phenomena, including the Rashba effect and topological insulators, highlighting its importance in modern condensed matter physics.