Correlation gap in the heavy-fermion antiferromagnet<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">UPd</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Al</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Dressel, Martin; Kasper, N. V.; Petukhov, K.; Peligrad, D.-N.; Gorshunov, B.; Jourdan, Martin; Huth, Michael; Adrian, H.

doi:10.1103/physrevb.66.035110

Cited by 38 publications

(45 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, the resistivity from 2 K up to 6.2 K (where a plot of In an earlier study [30], the temperature dependence of the DC resistivity of a thin film UPd 2 Al 3 was analyzed using a different expression and the gap was estimated to be 1.9 meV, larger than our value.…”

Section: Resistivity and Magnetic Susceptibilitymentioning

confidence: 67%

Hybridization gap in the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy

et al. 2017

View full text Add to dashboard Cite

We present results from point-contact spectroscopy of the antiferromagnetic heavy-fermion superconductor UPd 2 Al 3 : conductance spectra are taken from single crystals with two major surface orientations as a function of temperature and magnetic field, and analyzed using a theory of co-tunneling into an Anderson lattice. Spectroscopic signatures are clearly identified including the distinct asymmetric double-peak structure arising from the opening of a hybridization gap when a coherent heavy Fermi liquid is formed. Both the hybridization gap, found to be 7.2 ± 0.3 meV at 4 K, and the conductance enhancement above a flat background decrease upon increasing temperature. While the hybridization gap is extrapolated to remain finite up to ~28 K, close to the temperature around which the magnetic susceptibility displays a broad peak, the conductance enhancement vanishes at ~18 K, slightly above the antiferromagnetic transition temperature (T N  14 K). This rapid decrease of the conductance enhancement is understood as a consequence of the junction drifting away from the ballistic regime due to increased scattering off magnons associated with the localized U 5f electrons. This shows that while the hybridization gap opening is not directly associated with the antiferromagnetic ordering, its visibility in the conductance is greatly affected by the temperature-dependent magnetic excitations. Our findings are not only consistent with the 5f dual-nature picture in the literature but also shed new light on the interplay between the itinerant and localized electrons in UPd 2 Al 3 .

show abstract

Section: Resistivity and Magnetic Susceptibilitymentioning

confidence: 67%

Hybridization gap in the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Specifically optical studies have provided experimental access to the hybridization strength via direct observation of the hybridization gap ͑⌬͒ in the dissipative part of the optical conductivity ͓ 1 ͔͑͒. [7][8][9][10][11][12][13][14] These studies have also extensively verified the prediction of the PAM on the scaling between the hybridization gap and the effective mass: ͑ ⌬ T Coh ͒ 2 ϰ m * , where T Coh is the temperature below which coherent scattering between magnetic sites emerges. 8 There have also been recent studies of numerous Yb and Ce compounds, that have demonstrated a scaling between the size of ⌬ and T K , the Kondo temperature.…”

Section: Introductionmentioning

confidence: 92%

Optical signatures of momentum-dependent hybridization of the local moments and conduction electrons in Kondo lattices

et al. 2007

View full text Add to dashboard Cite

An analysis of the optical properties of heavy fermion compounds is reported. We focus on the 1-1-5 series, where strong deviations of the spectra are seen from the predictions of the periodic Anderson model. Specifically we demonstrate that the differences between the experimental results and the theoretical predictions can be explained by accounting for the momentum dependence of the hybridization between the local moments and the conducting carriers. Furthermore we find correlations between the hybridization strength on a particular band and some properties of the 1-1-5 compounds. These correlations suggest that the momentum dependence of the hybridization has to be taken into account, for an understanding of the electronic properties of these heavy fermion compounds.

show abstract

“…Such behavior is observed in many other heavy-fermion materials. [17,20,21,22] The m * (ω)/m 0 enhancement with decreasing temperature is accompanied by a formation of a broad peak in 1/τ (ω) in the energy region where the pseudogap-like suppression of σ(ω) appears as shown in Fig. 3b.…”

mentioning

confidence: 94%

Optical observation of non-Fermi-liquid behavior in the heavy fermion state ofYbRh2Si2

et al. 2006

View full text Add to dashboard Cite

We report far-infrared optical properties of YbRh2Si2 for photon energies down to 2 meV and temperatures 0.4 -300 K. In the coherent heavy quasiparticle state, a linear dependence of the lowenergy scattering rate on both temperature and photon energy was found. We relate this distinct dynamical behavior different from that of Fermi liquid materials to the non-Fermi liquid nature of YbRh2Si2 which is due to its close vicinity to an antiferromagnetic quantum critical point.PACS numbers: 71.10. Hf, 71.27.+a, The investigation of 4f -containing metals by farinfrared optical spectroscopy provides valuable insight into the nature of strong electronic correlations. This in particular holds true for heavy fermion (HF) compounds where at low temperatures a weak 4f -conduction electron (cf -)hybridization generates mass-renormalized quasiparticles with a coherent ground state which is in many HF systems of the Landau Fermi liquid (LFL) type.[1] The quasiparticles influence thermodynamic quantities which are described in terms of a large effective mass m * exceeding the free electron mass m 0 by three orders of magnitude. Furthermore, in typical HF materials, below a single-ion Kondo temperature (T K ), the coherent state is characterized by a dynamical screening of the 4f magnetic moments through the conduction electrons. Several highly correlated metals exhibit so-called nonFermi liquid (NFL), i.e., strong deviations from a renormalized LFL behavior when T → 0 K. [1] The system YbRh 2 Si 2 studied in this paper is one of a few clean stoichiometric HF metals with pronounced NFL behavior at ambient pressure which is related to both antiferromagnetic (AF) as well as ferromagnetic quantum critical spin fluctuations in close proximity to an AF quantum critical point (QCP). [2, 3, 4] Those NFL effects manifest as a divergence of the 4f -derived increment to the specific heat ∆C/T ∝ − ln T and in the electrical resistivity ρ(T ) showing a power law exponent close to 1 in a temperature range substantially larger than one decade and extending up to T ≃ 10 K.[5] Transport and thermodynamic properties are consistent with a single-ion Kondo temperature T K = 25 K (associated with the crystallineelectric-field-derived doublet ground state [6]).The electrodynamical response of HF systems is characterized by an optical conductivity σ(ω) which follows at room temperature the classical Drude model [σ(ω) = N e 2 τ /m * (1 + ω 2 τ 2 ); N : charge carrier density] with frequency independent m * and scattering rate 1/τ . [7] At low temperatures, upon entering the coherent state, large deviations are observed which are caused by many-body effects. Then a narrow, renormalized peak at zero photon energy ω = 0 eV is formed and a socalled hybridization gap appears which is related to the transition between the bonding and antibonding states resulting from the cf -hybridization. [8, 9, 10] The coherent part of the underlying strong electron-electron correlations are treated in an extended Drude model by renormalized and frequency dependent m * (ω)...

show abstract

Correlation gap in the heavy-fermion antiferromagnetUPd2Al3

Cited by 38 publications

References 79 publications

Hybridization gap in the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy

Hybridization gap in the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy

Optical signatures of momentum-dependent hybridization of the local moments and conduction electrons in Kondo lattices

Optical observation of non-Fermi-liquid behavior in the heavy fermion state ofYbRh2Si2

Contact Info

Product

Resources

About