Asymmetrical tunneling in heavy fermion metals as a possible probe for their non-Fermi liquid peculiarities

Shaginyan, V. R.; Попов, К. Г.; Stephanovich, V. A.; Кириченко, Е. В.

doi:10.1016/j.jallcom.2006.08.344

Cited by 15 publications

(35 citation statements)

References 12 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Weak asymmetry is seen at small magnetic fields. Thus, in accordance with prediction [1][2][3][4], the asymmetric part tends to zero at sufficiently high magnetic fields, as is seen from Fig. 8.…”

Section: Asymmetric Conductivity Of Heavy-fermion Compoundssupporting

confidence: 89%

“…Under application of a magnetic field B at sufficiently low temperatures k B T µ B B (k B and µ B are the Boltzmann constant and the Bohr magneton, respectively), the strongly correlated Fermi system transits from the NFL to the LFL regime [3]. As we have seen above, the asymmetry of the tunneling conductivity vanishes in the LFL state [1][2][3][4]. Figure 5 shows the differential conductivity σ d observed in measurements on YbRh 2 Si 2 [7,8].…”

Section: Asymmetric Conductivity Of Heavy-fermion Compoundsmentioning

confidence: 82%

“…4b. As a result, the asymmetric part of the differential conductivity ∆σ ) becomes finite and we obtain [1][2][3][4]6]:…”

Section: Asymmetric Conductivity Of Heavy-fermion Compoundsmentioning

confidence: 99%

“…It has been predicted that the conductivity becomes asymmetric for HF metals such as CeCoIn 5 and YbRh 2 Si 2 . As an underlying mechanism, it is posited in these materials that the electronic system undergoes a special kind of transformation: a portion of its singleparticle spectrum becomes dispersionless, forming a socalled flat band and leading to the asymmetrical conductivity [1][2][3][4]. Emergence of a flat band implies that the * corresponding author; e-mail: stef@uni.opole.pl system possesses a quantum critical point representing a topological instability.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Experimental Manifestations of Fermion Condensation in Strongly Correlated Fermi Systems

2019

Self Cite

View full text Add to dashboard Cite

Many strongly correlated Fermi systems including heavy-fermion (HF) metals and high-Tc superconductors belong to that class of quantum many-body systems for which the Landau-Fermi liquid theory fails. Instead, these systems exhibit non-Fermi-liquid properties that arise from violation of time-reversal (T) and particlehole (C) invariance. Here we consider two most recent experimental puzzles, which cannot be explained neither within the Landau-Fermi liquid picture nor can they be made intelligible by the approaches like the Hubbard model and/or the Kondo effect, which are commonly used to spell out the typical non-Fermi-liquid behavior. The first experimental puzzle is the asymmetric (with respect to bias voltage V) tunneling conductance (more specifically differential conductivity dI/ dV , where I is the current) of HF metals like CeCoIn5 and YbRh2Si2 and Leggett theorem violation in overdoped copper HTSC oxides. The second puzzle is strange properties of geometrically frustrated 2D magnets like herbertsmithite ZnCu3(OH)6Cl2, of which unusual properties are related to the emergence of so-called quantum spin liquid formed from fermionic spinons-the quasiparticles which substitute ordinary bosonic magnons in geometrically frustrated substances. It turns out that in both above classes of compounds, the background Fermi liquid (quantum spin liquid in geometrically frustrated magnets and electron liquid in other substances) is considered to undergo a transformation that renders a portion of its excitation spectrum dispersionless, giving rise to so-called flat bands. The presence of a flat band indicates that the system is close to a special quantum critical point, namely a topological fermion-condensation quantum phase transition. An essential aspect of the behavior of a system hosting a flat band is that application of a magnetic field restores its normal Fermi-liquid properties, including T-and C-invariance, thus removing above non-Fermi-liquid anomalies.

show abstract

Section: Asymmetric Conductivity Of Heavy-fermion Compoundssupporting

confidence: 89%

Section: Asymmetric Conductivity Of Heavy-fermion Compoundsmentioning

confidence: 82%

“…4b. As a result, the asymmetric part of the differential conductivity ∆σ ) becomes finite and we obtain [1][2][3][4]6]:…”

Section: Asymmetric Conductivity Of Heavy-fermion Compoundsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental Manifestations of Fermion Condensation in Strongly Correlated Fermi Systems

2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Under the application of magnetic field B at sufficiently low temperatures k B T µ B B, where k B and µ B are the Boltzmann constant and the Bohr magneton, the strongly correlated Fermi system transits from NFL to the LFL regime [2,26]. As we have seen above, the asymmetry of the tunneling conductivity vanishes in the LFL state [2,[13][14][15]. Figure 3 shows the differential conductivity σ d observed in measurements on YbRh 2 Si 2 [5,6].…”

Section: Asymmetric Conductivity and The Nfl Behaviormentioning

confidence: 86%

Flat bands and strongly correlated Fermi systems

et al. 2019

View full text Add to dashboard Cite

Some materials can have the dispersionless parts in their electronic spectra. These parts are usually called flat bands and generate the corps of unusual physical properties of such materials. These flat bands are induced by the condensation of fermionic quasiparticles [1-3], being very similar to the Bose condensation. The difference is that fermions to condense, the Fermi surface should change its topology [1-4], leading to violation of time-reversal (T) and particle-hole (C) symmetries. Thus, the famous Landau theory of Fermi liquids does not work for the systems with fermion condensate (FC) so that several experimentally observable anomalies have not been explained so far.Here we use FC approach to explain recent observations of the asymmetric tunneling conductivity in heavy-fermion compounds and graphene [5][6][7] and its restoration in magnetic fields, as well as the violation of Leggett theorem [8,9], recently observed experimentally [10,11] in overdoped cuprates, and recent observation of the challenging universal scaling connecting linear-T -dependent resistivity to the superconducting superfluid density [12].

show abstract

Asymmetric Conductivity of Strongly Correlated Compounds

Амусья¹,

Shaginyan²

2020

Springer Tracts in Modern Physics

View full text Add to dashboard Cite

Asymmetrical tunneling in heavy fermion metals as a possible probe for their non-Fermi liquid peculiarities

Cited by 15 publications

References 12 publications

Experimental Manifestations of Fermion Condensation in Strongly Correlated Fermi Systems

Experimental Manifestations of Fermion Condensation in Strongly Correlated Fermi Systems

Flat bands and strongly correlated Fermi systems

Asymmetric Conductivity of Strongly Correlated Compounds

Contact Info

Product

Resources

About