Energy level
能级 | Average number Maxwell- Boltzmann
平均麦克斯韦-玻尔兹曼数 | Average number Bose- Einstein
平均数玻色-爱因斯坦 |
| 0 | 2.143 | 2.269 |
| 1 | 1.484 | 1.538 |
| 2 | 0.989 | 0.885 |
| 3 | 0.629 | 0.538 |
| 4 | 0.378 | 0.269 |
| 5 | 0.210 | 0.192 |
| 6 | 0.105 | 0.115 |
| 7 | 0.045 | 0.077 |
| 8 | 0.015 | 0.038 |
| 9 | 0.003 | 0.038 |
| There are 26 possible distributions of 9 units of energy among 6 particles, and if those particles are indistinguishable and described by Bose-Einstein statistics, all of the distributions have equal probability. To get a distribution function of the number of particles as a function of energy, the average population of each energy state must be taken. The average for each of the 9 states is shown below compared to the result obtained by Maxwell-Boltzmann statistics.
有26种可能的能量分配方式,将9个单位的能量分配给6个粒子。如果这些粒子是不可区分的,并且由玻色-爱因斯坦统计描述,则所有分配方式的概率相等。为了得到粒子数随能量变化的分布函数,必须计算每个能量态的平均人口。下面显示了9个状态的平均值,与通过麦克斯韦-玻尔兹曼统计得到的结果进行比较。
Low energy states are more probable with Bose-Einstein statistics than with the Maxwell-Boltzmann statistics. While that excess is not dramatic in this example for a small number of particles, it becomes very dramatic with large numbers and low temperatures. At very low temperatures, bosons can "condense" into the lowest energy state. The phenomenon called Bose-Einstein condensation is observed with liquid helium and is responsible for its remarkable behavior.
低能态在玻色-爱因斯坦统计中比在麦克斯韦-玻尔兹曼统计中更可能。虽然在这个小粒子数的例子中,这种优势并不显著,但在大量粒子和低温下,这种差异会变得非常显著。在极低温下,玻色子可以‘凝聚’到最低能量态。这种称为玻色-爱因斯坦凝聚的现象在液氦中被观察到,并导致其非凡的行为。 |