What is the Fermi energy of Liquid He3 at absolute zero?

In summary, the atom He^3 has spin 1/2 and is a fermion. The density of liquid He^3 is 0.081g/cm^3 near absolute zero. To calculate the Fermi energy and Fermi temperature, we can use the equations \epsilon_F = \frac{\hbar^2}{2m}(\frac{3 \pi^2 N}{V})^{2/3} and T_F = \frac{\epsilon_F}{k}. However, it is important to note that number density should be used instead of straight density to ensure correct units.
  • #1
atomicpedals
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Homework Statement



The atom [itex]He^3[/itex] has spin 1/2 and is a fermion. The density of liquid [itex]He^3[/itex] is [itex]0.081g/cm^3[/itex] near absolute zero. Calculate the Fermi energy [itex]\epsilon_F[/itex] and the Fermi temperature [itex]T_F[/itex]

Homework Equations



[itex]\epsilon_F = \frac{\hbar^2}{2m}(\frac{3 \pi^2 N}{V})^{2/3}[/itex]

[itex]T_F = \frac{\epsilon_F}{k}[/itex]

The Attempt at a Solution



In the problem I'm given the density is [itex]0.081g/cm^3[/itex], which is my N/V. Assuming that m is the mass of [itex]He^3[/itex], then [itex]m = 5.008*10^{-24}g[/itex]. I should then be able to do a straight forward plug-n-chug; however my units don't work out as I get:

[itex]\epsilon_F = \frac{\hbar^2}{1.0016*10^{-23}g}(3 \pi^2 0.081g cm^{-3})^{2/3}=1.99*10^{-50} kg^{5/3} m^2 s^{-2}[/itex]

Clearly, this is not a unit of energy. What am I doing wrong?
 
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  • #2
I need to use number density, rather than straight density. Which should take care of my problem.
 

1. What is the Fermi energy of liquid He3?

The Fermi energy of liquid He3 is the energy level at which the highest occupied state of the electrons in the liquid reaches when it is at absolute zero temperature. In other words, it is the highest energy level at which electrons are still present in the liquid.

2. How is the Fermi energy of liquid He3 calculated?

The Fermi energy of liquid He3 can be calculated using the formula E_F = (3nπ^2h^2)^(2/3)/(8m), where n is the number density of the liquid, h is Planck's constant, and m is the mass of a He3 atom.

3. What factors affect the Fermi energy of liquid He3?

The Fermi energy of liquid He3 is affected by the number density of the liquid, the mass of the He3 atoms, and the temperature of the liquid. It also depends on the external pressure and the magnetic field applied to the liquid.

4. How does the Fermi energy of liquid He3 influence its properties?

The Fermi energy of liquid He3 plays a significant role in determining the electrical and thermal conductivity of the liquid. It also affects the magnetic properties and the superfluid behavior of the liquid.

5. Can the Fermi energy of liquid He3 be measured experimentally?

Yes, the Fermi energy of liquid He3 can be measured experimentally using various techniques such as photoemission spectroscopy and tunneling spectroscopy. These methods involve measuring the energy levels of electrons in the liquid to determine the Fermi energy.

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