All Questions
Tagged with fermi-liquids solid-state-physics
15
questions
10
votes
1
answer
898
views
Finite quasiparticle lifetimes in Fermi Liquid Theory
I am trying to clarify a conceptual issue about phenomenological Fermi liquid theory. My confusion can be explained using the following two sentences from Dupuis's many body theory notes, but the same ...
- 3,098
2
votes
1
answer
96
views
Mermin's derivation on the existence of zero sound
I have a question concerning Mermin's 1967 paper "Existence of Zero Sound in a Fermi Liquid". The condition on zero sound is given by the equation
$$\lambda_n>\eta^{-1}\int \frac{d\hat{n}}...
- 2,665
3
votes
1
answer
116
views
Calculating the inelastic quasiparticle lifetime of a screened quantum fluid
I've been studying "Lifetime of a quasiparticle in an electron liquid", by Qian and Vignale. Much of it makes sense, but there is a detail in the calculation of the exchange term that doesn't make ...
- 2,665
2
votes
1
answer
252
views
Negative curvature of zero sound dispersion
In the theory of a Landau-Fermi liquid, one of the major predictions is the dispersion of zero sound. From the linearized kinetic equation, we know that the dimensionless dispersion $s$ is given by
$$ ...
- 2,665
3
votes
1
answer
469
views
Why do we have to introduce quasiparticles in the Fermi liquid theory
Why is it necessary in Fermi liquid theory to introduce quasiparticles? I understand the notion of system where someone can turn on the interactions slowly (i.e., adiabatically), but I do not ...
- 437
2
votes
1
answer
400
views
Is there a physical meaning of the Fermi liquid parameters
In Fermi liquid theory we define two parameters $F_l^s = VN(\epsilon_F)u_l^s$ and $F_l^a = VN(\epsilon_F)u_l^a$ where V is the fermi-volume, $N(\epsilon_F)$ the density of states at the Fermi energy ...
- 437
1
vote
0
answers
1k
views
Fermi liquid vs Fermi gas, when to use either one to model a metal?
I had been taught to consider electrons as a Fermi gas in order to calculate properties (like the heat capacity for instance) of metals even near $T=0K$.
However I'm now discovering Fermi liquids on ...
4
votes
1
answer
251
views
Discontinuity of Fermi liquid occupancy
In Fermi liquid theory, the electron spectral function is often represented by $$A(k,\omega) = Z\delta(\omega-\epsilon_k)\ + \text{incoherent background} $$ where $Z$ is the weight in the ...
- 4,016
5
votes
2
answers
2k
views
Why does the free electron theory of metals work?
Free electron theory of metals works unreasonably well in spite of the fact that we neglect the Coulomb repulsion between the electrons. Is there deeper reason why this should work? Somewhere I heard ...
- 26.8k
9
votes
0
answers
1k
views
Failure of Hertz-Millis-Moriya theory for quantum phenomena
In the quantum critical phenomena of condensed matter, the earlier work by Hertz, Moriya and Millis develope the the Hertz-Millis-Moriya (HMM) theory of quantum phase transition.
Naively, they ...
- 7,848
3
votes
2
answers
484
views
Fermi "surface" at finite temperature and its measurement in the lab
As we increase the temperature, we know the sharp Fermi surface at zero temperature becomes smeared out at finite temperature $T>0$. (Just think of the Fermi-Dirac distribution, there will be no ...
user32229
2
votes
0
answers
115
views
The validity of infinite many Conformal Field Theories on the Fermi surface
The naive $2$-dimensional Fermi sea in $k$-space (with a convex structure and positive Gaussian curvature, some nice properties, etc) in $2+1$-dimensional spacetime may be viewed as an infinite ...
- 7,848
1
vote
0
answers
47
views
Conventional Landau orders and non-conventional orders in the pseudogap of cuprate
What kind of conventional Landau orders have been seen in the pseudogap phase of cuprate? Such as Spin-Density Wave, Charge-Density Wave, etc? What are the most influential/representative journal Refs ...
- 7,848
3
votes
1
answer
89
views
Experimental confirmation of the finite jump of the occupation number at the Fermi surface
It is a well-known result in Fermi-liquid theory that the occupation number has a finite jump at the Fermi surface. But, is it confirmed experimentally?
- 4,122
1
vote
0
answers
39
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Properties of materials _not_ dependent on fermi surface?
So I'm studying a second solid state physics course where we've covered calculating things like magnetic susceptibility, specific heat and resistivity by considering excitations of electrons around ...
- 178