Luttinger's theorem

In condensed matter physics, Luttinger's theorem[1][2] is a result derived by J. M. Luttinger and J. C. Ward in 1960 that has broad implications in the field of electron transport. It arises frequently in theoretical models of correlated electrons, such as the high-temperature superconductors, and in photoemission, where a metal's Fermi surface can be directly observed.

Luttinger's theorem relates a Fermi liquid's particle density to the volume of its Fermi surface.

Definition

Luttinger's theorem states that the volume enclosed by a material's Fermi surface is directly proportional to the particle density.

While the theorem is an immediate result of the Pauli exclusion principle in the case of noninteracting particles, it remains true even as interactions between particles are taken into consideration provided that the appropriate definitions of Fermi surface and particle density are adopted. Specifically, in the interacting case the Fermi surface must be defined according to the criteria that

or

where is the single-particle Green function in terms of frequency and momentum. Then Luttinger's theorem can be recast into the form[3]

,

where is as above and is the differential volume of -space in dimensions.

gollark: I have another one in an hour.
gollark: <@&358173303816323072> Can someone catch my experiment in ~15 minutes?
gollark: Anyone available in 5ish hours? I have two experiments running.
gollark: Smallish ND experiments don't really say much about the effectiveness of various things, because NDs are highly random, and there don't seem to be any attempts to do larger-scale ND experiments which control for the many variables involved.
gollark: I've done neglection a bit last year, which is where I got... some stuff or other, I forget... from.

See also

References

Inline

  1. Luttinger, J. M.; Ward, J. C. (1960). "Ground-State Energy of a Many-Fermion System. II". Physical Review. 118 (5): 1417–1427. Bibcode:1960PhRv..118.1417L. doi:10.1103/PhysRev.118.1417.
  2. Luttinger, J. M. (1960). "Fermi Surface and Some Simple Equilibrium Properties of a System of Interacting Fermions". Physical Review. 119 (4): 1153–1163. Bibcode:1960PhRv..119.1153L. doi:10.1103/PhysRev.119.1153.
  3. Alexei M. Tsvelik (2003). Quantum Field Theory in Condensed Matter Physics (2nd ed.). Cambridge University Press. p. 327. ISBN 978-0-521-82284-8.

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