Licchavi Lyceum


Licchavi Lyceum

Bose Einstein Distribution Law

The Bose-Einstein distribution is a statistical distribution that describes the distribution of particles with integer spin, called bosons, in a system at thermal equilibrium. It provides insights into the probabilities associated with different energy levels and allows for the calculation of various properties of the system, such as average occupation number and energy distribution.

The distribution is derived based on the principles of quantum statistics and assumes that the bosons follow quantum mechanics. It is applicable to systems where the particles are indistinguishable, and multiple particles can occupy the same quantum state simultaneously, following the Bose-Einstein statistics.

The Bose-Einstein distribution is derived as follows:

  1. Consider a system of bosons at thermal equilibrium.
  2. The distribution assumes that the bosons occupy discrete energy levels, and there is a range of possible energy levels.
  3. The distribution function, denoted as n(E), represents the average number of bosons occupying an energy level E.
  4. The Bose-Einstein distribution function is given by:

    n(E) = 1 / (e^(E – μ) / (kT) – 1)


    • E is the energy of a specific energy level
    • μ is the chemical potential of the system
    • k is Boltzmann’s constant
    • T is the temperature of the system in Kelvin
  5. The distribution function shows that the average occupation number is inversely related to the energy level. Lower energy levels have higher average occupation numbers, while higher energy levels have lower average occupation numbers.
  6. The distribution also introduces the concept of chemical potential (μ), which determines the average energy per particle and controls the total number of particles in the system. The chemical potential ensures that the average number of particles remains conserved.

The Bose-Einstein distribution provides important insights into the behavior of bosonic systems. Some key properties and applications include:

  • Average Occupation Number: The distribution allows us to calculate the average occupation number, which represents the average number of bosons occupying a specific energy level. It provides information about the population distribution among different energy levels.
  • Energy Distribution: The distribution provides information about the probabilities associated with different energy levels. It describes the distribution of energy among the bosons in the system.
  • Bose-Einstein Condensation: At low temperatures, when the chemical potential reaches a critical value, a macroscopic number of bosons can occupy the lowest energy state. This phenomenon is known as Bose-Einstein condensation and is a unique behavior of bosonic systems described by the Bose-Einstein distribution.
  • Applications: The Bose-Einstein distribution is utilized in various fields, including the study of superfluidity, superconductivity, and the behavior of bosonic particles in quantum gases and lasers.

The Bose-Einstein distribution provides a statistical description of the behavior of bosonic particles, allowing us to understand their energy distribution and calculate various properties associated with bosonic systems.