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.

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 interaction between the particles of the many-body system does not need to be small. The phenomenological theory of Fermi liquids was introduced by the Soviet physicist Lev Davidovich Landau in 1956, and later developed by Alexei Abrikosov and I. M. Khalatnikov using diagrammatic perturbation theory. The theory explains why some of the properties of an interacting fermion system are very similar to those of the Fermi gas (i.e. non-interacting fermions), and why other properties differ. More on Wikipedia.

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Strong interacting v.s. Strong Coupling v.s. Strong Correlated

One of the active research areas in present is Strong interacting, Strong Coupling, Strong Correlated regime of the phases of matters. It seems to me that some physicists in the fields often mix the usages of these twos: Strong Coupling, Strong…
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What "transformations" did Abrikosov use in 1958 to get the famous $11-2\log{2}$ result in fermi-liquid theory?

How does one obtain the final integral expression in the appendix of Abrikosov and Khalatnikov's 1958 paper: $\ \ \ $ "Concerning a model for a non-ideal fermi gas" $\ \ \ $ ??? Below, in Bold, I will mark the point at which I am stuck. The paper…
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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 sentiment is present in many other sources as…
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The "dangerous" fixed points for Renormalization Group

What is the definition of dangerously irrelevant renormalization-group (RG) fixed point? What are some examples of dangerously irrelevant RG fixed points? Do we also have the use of dangerously relevant RG fixed points? Do we also have the use of…
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Fermi Liquid Theory Reference

I am trying to study Fermi liquid theory as a primer to understand what so-called non-Fermi liquids are. In particular, I want to understand the predictions of Fermi liquid theory (such as temperature dependence of observables), how they are…
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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 integrate out Fermi surface quasiparticles and obtain an…
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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 then, whether one can perform a canonical…
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Why gapped systems are called incompressible?

I study quantum Hall systems and I haven't studied Fermi liquid theory yet. But I understand the concept of having gap or being gapless. But why do we use the term incompressibility to correspond the presence of gap in the bulk state? Is there any…
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Is that possible to derive Landau-Fermi liquid theory from microscopic equation?

This question arises from reading Wen's book "Quantum Field Theory of Many-body Systems (Oxford 2004)" p204 To appreciate the brilliance of Landau-Fermi liquid theory, let us look at the many-body Hamiltonian of interacting electrons, namely …
user26143
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Why is the density of the Fermi gas in a neutron star not changing the potential depth caused by the strong nuclear interaction?

In some textbooks, the neutron star is explained as a degenerate Fermi gas. To calculate the degenerate pressure of the neutron fermi gas the average Energy of a neutron, U is calculated when the Volume V is changed. p = dU/dV. However, this does…
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Self-energy of a Fermi liquid

A weakly correlated many-electron system can be viewed in a first approximation as a Fermi liquid, meaning that it behaves similarly to a non-interacting electron gas with renormalized parameters. In this respect, one can calculate the electronic…
Dimitri
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Quasiparticle density of states : how to give it a meaning as the quasi particle are interacting?

There is something I don't understand about quasiparticles density of states. I work with the book "Introduction to many body physics" from Coleman. When he introduces the quasiparticle he does the following. We consider a Fermi sea of a non…
StarBucK
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Volovik's argument and superconductivity

In Volovik's book he describes the Fermi surface as a vortex in energy+momentum space. Due to a winding number the Fermi surface is topologically protected. I don't understand how the above topological protection is compatible with…
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Why quasiparticles do not decay in finite system in random phase approximation?

I have tried to apply the conventional recipe of calculating electron self-energy part $\Sigma$ in the random phase approximation (RPA) to the case of finite system and obtained $\mathrm{Im}\,\Sigma=0$, i.e. that the quasiparticle does not…
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What is a marginal fermi liquid in a nutshell?

I would like to know what are the main differences between the normal Fermi liquid theory and a marginal fermi liquid theory. What kind of systems can be described by the marginal liquid theory? What are the consequences of considering an electron…
Alíz
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