Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:cond-mat/9907061

The interplay between flattening and damping of single particle spectra in strongly correlated Fermi systems

VICTOR A. KHODEL, MIKHAIL V. ZVEREV

Published Jul 5, 1999• 0 citations
arXivHTMLPDF

Abstract

The self-consistent theory of the fermion condensation, a specific phase transition which results in a rearrangement of the single particle degrees of freedom in strongly correlated Fermi systems is developed. Beyond the phase transition point, the single particle spectra are shown to be flat. The interplay between the flattening and the damping of the single particle spectra at $T\to 0$ is investigated. The width $γ(ε)$ of the single particle states is found to grow up linearly with $ε$ over a wide range of energy as in a marginal Fermi liquid. Our results gain insight into the success of the phenomenological theory of the normal states of high-temperature superconductors by Varma et al.

DOI
10.48550/arxiv.cond-mat/9907061

Related papers

A simplified model for the rearrangement of single-particle degrees of freedom near the point of antiferromagnetic phase transition in strongly correlated Fermi systems

MIKHAIL V. ZVEREV, VICTOR A. KHODEL, J. W. Clark

It is shown that the antiferromagnetic transition is preceded by the fermion condensation with rearrangement of single-particle degrees of freedom and appearance of plateaus in the spectrum of single-particle excitations. The results obtained are used to explain the gap structure in the spectrum of two-dimensional high-T c superconductors at T=0.

Journal of Experimental and Theoretical Physics Letters•Jul 1, 2001•10 citations

NON-FERMI-LIQUID BEHAVIOR FROM THE FERMI-LIQUID APPROACH

VICTOR A. KHODEL, J. W. Clark, H. Li +2 more

Non-Fermi liquid behavior of strongly correlated Fermi systems is derived within the Landau approach. We attribute this behavior to a phase transition associated with a rearrangement of the Landau state that leads to flattening of a portion of the single-particle spectrum $ε({\bf p})$ in the vicinity of the Fermi surface. We demonstrate that the quasiparticle subsystem responsible for the flat spectrum possesses the same thermodynamic properties as a gas of localized spins. Theoretical results compare favorably with available experimental data. While departing radically from prevalent views on the origin of non-Fermi-liquid behavior, the theory advanced here is nevertheless a conservative one of in continuing to operate within the general framework of Landau theory.

arXiv:0710.5296•Sep 1, 2007•0 citations

Spin degrees of freedom and flattening of the spectra of single-particle excitations in strongly correlated Fermi systems

V. A. Khodel, Peter Schuck, M. V. Zverev

The impact of long-range spin-spin correlations on the structure of a flat portion in single-particle spectra ξ ( p ), which emerges beyond the point where the Landau state loses its stability, is studied. We supplement the well-known Nozieres model of a Fermi system with limited scalar long-range forces by a similar long-range spin-dependent term and calculate the spectra versus its strength g . It is found that Nozieres' results hold as long as g >0. However, with g changing its sign, the spontaneous magnetization is shown to arise at any nonzero g . The increase in the strength | g | is demonstrated to result in shrinkage of the domain in momentum space, occupied by the flat portion of ξ ( p ), and, eventually, in its vanishing.

arXiv:cond-mat/0308309•Physics of Atomic Nuclei•Oct 1, 2003•2 citations

Thermodynamic properties of Fermi systems with flat single-particle spectra

V. A Khodel, J. W Clark, M. V Zverev

The behavior of strongly correlated Fermi systems is investigated beyond the onset of a phase transition where the single-particle spectrum ξ( p ) becomes flat. The Landau-Migdal quasiparticle picture is shown to remain applicable on the ordered side of this transition. Nevertheless, low-temperature properties evaluated within this picture show profound changes relative to results of Landau theory, as a direct consequence of the flattening of ξ( p ). Stability conditions for this class of systems are examined, and the nature of antiferromagnetic quantum phase transitions is elucidated.

arXiv:cond-mat/0502292•Europhysics Letters (EPL)•Sep 20, 2005•9 citations

NON-FERMI-LIQUID BEHAVIOR FROM THE FERMI-LIQUID APPROACH

VICTOR A. KHODEL, J. W. Clark, H. Li +2 more

Non-Fermi liquid behavior of strongly correlated Fermi systems is derived within the Landau approach. We attribute this behavior to a phase transition associated with a rearrangement of the Landau state that leads to flattening of a portion of the single-particle spectrum ∊(p) in the vicinity of the Fermi surface. We demonstrate that the quasiparticle subsystem responsible for the flat spectrum possesses the same thermodynamic properties as a gas of localized spins. Theoretical results compare favorably with available experimental data. While departing radically from prevalent views on the origin of non-Fermi-liquid behavior, the theory advanced here is nevertheless a conservative one of in continuing to operate within the general framework of Landau theory.

International Journal of Modern Physics B•May 30, 2007•1 citation

Quasiparticle picture of high-temperature superconductors in the frame of a Fermi liquid with the fermion condensate

M. Ya. Amusia, Vasily R. Shaginyan

A model of a Fermi liquid with the fermion condensate (FC) is applied to the consideration of quasiparticle excitations in high-temperature superconductors, in their superconducting and normal states. Within our model the appearance of the fermion condensate presents a quantum phase transition that separates the regions of normal and strongly correlated electron liquids. Beyond the phase transition point the quasiparticle system is divided into two subsystems, one containing normal quasiparticles and the other---fermion condensate localized at the Fermi surface and characterized by almost dispersionless single-particle excitations. In the superconducting state the quasiparticle dispersion in systems with FC can be presented by two straight lines, characterized by effective masses ${M}_{\mathrm{FC}}^{*}$ and ${M}_{L}^{*},$ respectively, and intersecting near the binding energy, which is of the order of the superconducting gap. This same quasiparticle picture persists in the normal state, thus manifesting itself over a wide range of temperatures as new energy scales. Arguments are presented that fermion systems with FC have features of a ``quantum protectorate'' [R. B. Laughlin and D. Pines, Proc. Natl. Acad. Sci. U.S.A. 97, 28 (2000); P. W. Anderson, cond-mat/0007185 (unpublished); cond-mat/0007287 (unpublished)].

arXiv:cond-mat/0102229•Physical review. B, Condensed matter•May 21, 2001•31 citations
The self-consistent theory of the fermion condensation, a specific phase transition which results in a rearrangement of the single particle degrees of freedom in strongly correlated Fermi systems is developed. Beyond the phase transition point, the single particle spectra are shown to be flat. The interplay between the flattening and the damping of the single particle spectra at T→0T\to 0T→0 is investigated. The width γ(ε)γ(ε)γ(ε) of the single particle states is found to grow up linearly with εεε over a wide range of energy as in a marginal Fermi liquid. Our results gain insight into the success of the phenomenological theory of the normal states of high-temperature superconductors by Varma et al.
Non-Fermi liquid behavior of strongly correlated Fermi systems is derived within the Landau approach. We attribute this behavior to a phase transition associated with a rearrangement of the Landau state that leads to flattening of a portion of the single-particle spectrum ε(p)ε({\bf p})ε(p) in the vicinity of the Fermi surface. We demonstrate that the quasiparticle subsystem responsible for the flat spectrum possesses the same thermodynamic properties as a gas of localized spins. Theoretical results compare favorably with available experimental data. While departing radically from prevalent views on the origin of non-Fermi-liquid behavior, the theory advanced here is nevertheless a conservative one of in continuing to operate within the general framework of Landau theory.
The impact of long-range spin-spin correlations on the structure of a flat portion in single-particle spectra ξ ( p ), which emerges beyond the point where the Landau state loses its stability, is studied. We supplement the well-known Nozieres model of a Fermi system with limited scalar long-range forces by a similar long-range spin-dependent term and calculate the spectra versus its strength g . It is found that Nozieres' results hold as long as g >0. However, with g changing its sign, the spontaneous magnetization is shown to arise at any nonzero g . The increase in the strength | g | is demonstrated to result in shrinkage of the domain in momentum space, occupied by the flat portion of ξ ( p ), and, eventually, in its vanishing.
The behavior of strongly correlated Fermi systems is investigated beyond the onset of a phase transition where the single-particle spectrum ξ( p ) becomes flat. The Landau-Migdal quasiparticle picture is shown to remain applicable on the ordered side of this transition. Nevertheless, low-temperature properties evaluated within this picture show profound changes relative to results of Landau theory, as a direct consequence of the flattening of ξ( p ). Stability conditions for this class of systems are examined, and the nature of antiferromagnetic quantum phase transitions is elucidated.
Non-Fermi liquid behavior of strongly correlated Fermi systems is derived within the Landau approach. We attribute this behavior to a phase transition associated with a rearrangement of the Landau state that leads to flattening of a portion of the single-particle spectrum ∊(p) in the vicinity of the Fermi surface. We demonstrate that the quasiparticle subsystem responsible for the flat spectrum possesses the same thermodynamic properties as a gas of localized spins. Theoretical results compare favorably with available experimental data. While departing radically from prevalent views on the origin of non-Fermi-liquid behavior, the theory advanced here is nevertheless a conservative one of in continuing to operate within the general framework of Landau theory.
A model of a Fermi liquid with the fermion condensate (FC) is applied to the consideration of quasiparticle excitations in high-temperature superconductors, in their superconducting and normal states. Within our model the appearance of the fermion condensate presents a quantum phase transition that separates the regions of normal and strongly correlated electron liquids. Beyond the phase transition point the quasiparticle system is divided into two subsystems, one containing normal quasiparticles and the other---fermion condensate localized at the Fermi surface and characterized by almost dispersionless single-particle excitations. In the superconducting state the quasiparticle dispersion in systems with FC can be presented by two straight lines, characterized by effective masses MFC∗{M}_{\mathrm{FC}}^{*}MFC∗​ and ML∗,{M}_{L}^{*},ML∗​, respectively, and intersecting near the binding energy, which is of the order of the superconducting gap. This same quasiparticle picture persists in the normal state, thus manifesting itself over a wide range of temperatures as new energy scales. Arguments are presented that fermion systems with FC have features of a ``quantum protectorate'' [R. B. Laughlin and D. Pines, Proc. Natl. Acad. Sci. U.S.A. 97, 28 (2000); P. W. Anderson, cond-mat/0007185 (unpublished); cond-mat/0007287 (unpublished)].