Questions tagged [fermi-liquids]
Fermi liquid theory (also known as Landau–Fermi liquid theory) is a theoretical model of interacting fermions that describes the normal state of most metals at sufficiently low temperatures. The phenomenological theory of Fermi liquids was introduced by the Soviet physicist Lev Davidovich Landau in 1956.
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Can Bose-Einstein condensates and Fermionic condensates survive for long periods of time in space?
Imagine we have a cold region of the universe, almost devoid of matter and radiation. Or perhaps in a future universe where the CMB has "cooled" down to sufficiently low "temperatures&...
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Momentum distribution Fermi liquid and spectral representation
In a Fermi liquid the momentum distribution shows a jump at the Fermi surface, i.e.
\begin{equation}\langle n_{k_F-\delta k} - n_{k_F+\delta k}\rangle = Z_{k_F}\end{equation}
with $Z_k$ the strength ...
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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 ...
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Chemical Potential of a Fermionic System
If the chemical potential of a fermionic system is $0$ at temperature $T=0$, will it be zero at any arbitrary finite temperature?
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How to find plasmon from Landau-Silin equation?
In David Pine's Theory Of Quantum Liquids: Normal Fermi Liquids, it's said that we can find charged Fermi liquid has plasmon modes easily from Eq. (3.40), replicated as follows:
$$
(\boldsymbol{q} \...
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Quasi-particle distribution in Fermi liquid theory
In Fermi liquid theory, the quasi-particle is well-defined only near the Fermi surface. However, in calculating specific heat and compressibility, we also assume that the quasi-particle obeys the ...
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Is (Landau's) Fermi liquid theroy a classical theory?
As a person majoring in condensed matter physics, I frequently encounter Landau Fermi-liquid theory. Almost every literature says that the concept of the adiabatic continuity (to the non-interacting ...
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Unitary Fermi Gas vs. Fermi Liquid
The unitary limit of a Fermi gas is described here as when the scattering length is comparable or exceeds the interparticle distance. For $ak_F<0$, this is the BCS limit of a weakly interacting ...
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Negative curvature of zero sound dispersion
In the theory of a Landau-Fermi liquid, one of the major predictions is the dispersion of zero sound. From the linearized kinetic equation, we know that the dimensionless dispersion $s$ is given by
$$ ...
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Pauli Exclusion Principle in Landau Fermi's liquid theory
I do not understand how Pauli exclusion principle helps us to understand the excitations in Landau Fermi's liquid theory. In Landau Fermi liquid theory, Pauli exclusion principle and adiabatic ...
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Can Fermi liquid be obtained by a canonical transformation?
The basic assumption of the Ferm-liquid theory is the one-to-one correspondence between the states of an interacting Fermi gas to those of a gas of non-interacting quasiparticles. The question is ...
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Is is possible to extract an effective Hamiltonian from a Boltzmann equation (or any other kinetic theories)?
I got kind of confused when reading Xiaogang Wen's famous textbook Quantum Field Theory of Many-body Systems. In Section 5.3.3 the book claims that
From a kinetic theory of Fermi liquid (a Boltzmann ...
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Gas to liquid phase transitions for electronic matter
Regular atomic matter almost always experiences liquid-gas transition at some temperature (at sufficiently low pressure). Does anyone know if electrons in metals/semiconductors experience a similar ...
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Hertz-Millis theory and quantum criticality
Hartz-Millis(HM) theory is a model which exhibits quantum phase transition. The HM action following Altland & Simons is given by
$$
S = \frac{1}{\beta}\sum_{\omega_{n}}\int \frac{d^d q}{(2\pi)^d}\...
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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 ...