Chemical Potential for Bosonic Particles

In summary, the problem being discussed is problem 5.29 (b) in Griffiths QM, which asks to show that the chemical potential (m(T)) monotonically increases as temperature (T) decreases, assuming N and V are constants. The solution involves differentiating m(T) and using the fact that dE/dT > 0 to show that m(T) is an increasing function of T. As T approaches 0, E also approaches 0, leading to the conclusion that m(T) must be negative.
  • #1
YAHA
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Homework Statement


I am working Problem 5.29 *** (b) in Griffiths QM. We are asked to show that m(T) monotonically increases as T decreases, assuming N and V are constants. m(T) - is chemical potential.



Homework Equations



Too many to list, probably easier to look in the book if you have it.

The Attempt at a Solution



Honestly, I played with this for 2 hours. I also have the solutions manual. Even after looking there, the logic is completely incomprehensible. Specifically, he concludes that as T->0, E->0 and thus, m(T) must be negative. This step is not evident at all (as are many others in Griffiths books and solutions manuals).



 
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  • #2
I would really appreciate some help. The solution goes something like this: m(T) = (2/V)[NkTln(2)+(2π2/3)N2/2V2/3T2/3] Differentiating with respect to T: dm/dT = -(2/VT)[N(2π2/3)N2V-2/3T-1/2]Using the fact that dE/dT > 0 we get: dm/dT > 0 This means that m(T) is an increasing function of T As T--> 0, E --> 0 and thus m(T) must be negative.
 

FAQ: Chemical Potential for Bosonic Particles

What is chemical potential for bosonic particles?

Chemical potential for bosonic particles is a thermodynamic quantity that represents the energy required to add one particle to a system of bosons at constant temperature, volume, and number of particles.

How is chemical potential for bosonic particles different from that of fermionic particles?

Unlike fermions, bosons can occupy the same quantum state, so bosonic chemical potential is typically zero or negative, while fermionic chemical potential is always positive.

What is the relationship between chemical potential and Bose-Einstein condensation?

At low temperatures, bosons can undergo Bose-Einstein condensation, where a large number of particles occupy the same quantum state. In this case, the chemical potential is equal to the energy of the particles in the condensate.

How does the chemical potential for bosonic particles change with temperature?

As temperature increases, the chemical potential for bosons decreases. This is because at higher temperatures, more energy is available for the particles to occupy different quantum states, reducing the need for additional particles to be added to the system.

Can chemical potential for bosonic particles be negative?

Yes, in some cases, the chemical potential for bosonic particles can be negative. This occurs when the temperature is below the critical temperature for Bose-Einstein condensation, and the particles are in a non-condensed state. In this case, the negative chemical potential indicates that adding particles to the system would lower the energy.

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