» 量子统计

量子统计

1926
  • Satyendra Nath Bose
  • Albert Einstein
  • Enrico Fermi
  • Paul Dirac
研究实验室重点研究量子统计在半导体物理学和激光器中的应用。

Quantum statistics modifies classical statistical 力学 to account for the indistinguishability of identical particles. It splits into two types: Fermi-Dirac statistics for fermions (half-integer spin particles like electrons), which obey the Pauli exclusion principle, and Bose-Einstein statistics for bosons (integer spin particles like photons), which can occupy the same quantum state. This distinction is crucial at low temperatures and high densities.

Classical Maxwell-Boltzmann statistics assumes that particles in a system are distinguishable, meaning one could, in principle, label and track each one. However, quantum mechanics revealed that identical particles are fundamentally indistinguishable. This leads to profound changes in how microstates are counted. For bosons, multiple particles can occupy a single energy state, leading to an enhanced probability of collective behavior. The average occupation number of a state with energy [latex]\epsilon_i[/latex] is given by the Bose-Einstein distribution: [latex]\langle n_i \rangle_{BE} = \frac{1}{e^{(\epsilon_i – \mu)/k_B T} – 1}[/latex]. This can lead to a macroscopic number of particles collapsing into the ground state at low temperatures, forming a Bose-Einstein condensate.

For fermions, the Pauli exclusion principle forbids any two identical particles from occupying the same quantum state. This ‘repulsive’ statistical effect gives rise to the structure of atoms and the stability of matter. The average occupation number is given by the Fermi-Dirac distribution: [latex]\langle n_i \rangle_{FD} = \frac{1}{e^{(\epsilon_i – \mu)/k_B T} + 1}[/latex]. This function is always less than or equal to 1. At absolute zero, fermions fill up all available energy levels up to a maximum energy called the Fermi energy. This creates a ‘Fermi sea’ and is responsible for the pressure that supports white dwarf stars against gravitational collapse. At high temperatures, both quantum distributions converge to the classical Maxwell-Boltzmann distribution.

UNESCO Nomenclature: 2211
- 热力学

类型

抽象系统

中断

革命

使用方法

广泛使用

前体

  • Planck’s law of black-body radiation, which implicitly treated photons as bosons
  • The Pauli exclusion principle, which is the foundation of Fermi-Dirac statistics
  • De Broglie’s hypothesis of wave-particle duality
  • Classical Maxwell-Boltzmann statistical mechanics

应用

  • semiconductor physics and the operation of transistors
  • superconductivity and superfluidity
  • the theory of white dwarf and neutron stars
  • the operation of lasers (based on properties of bosons)
  • bose-einstein condensates

专利:

NA

潜在的创新想法

级别需要会员

您必须是!!等级!!会员才能访问此内容。

立即加入

已经是会员? 在此登录
Related to: quantum statistics, Fermi-Dirac, Bose-Einstein, fermions, bosons, Pauli exclusion principle, Bose-Einstein condensate, quantum mechanics.

发表回复

您的邮箱地址不会被公开。 必填项已用 * 标注

迎接新挑战
机械工程师、项目、工艺工程师或研发经理
有效的产品开发

可在短时间内接受新的挑战。
通过 LinkedIn 联系我
塑料金属电子集成、成本设计、GMP、人体工程学、中高容量设备和耗材、精益制造、受监管行业、CE 和 FDA、CAD、Solidworks、精益西格玛黑带、医疗 ISO 13485

我们正在寻找新的赞助商

 

您的公司或机构从事技术、科学或研究吗?
> 给我们发送消息 <

接收所有新文章
免费,无垃圾邮件,电子邮件不分发也不转售

或者您可以免费获得完整会员资格以访问所有受限制的内容>这里<

历史背景

(如果日期不详或不相关,例如 "流体力学",则对其显著出现的时间作了四舍五入的估计)。

相关发明、创新和技术原理

滚动至顶部

你可能还喜欢