skip to main content

DOE PAGESDOE PAGES

Title: Hybridization gap and dual nature of the heavy-fermion compound UPd 2Al 3 via quasiparticle scattering spectroscopy

We present results from point-contact spectroscopy of the antiferromagnetic heavy-fermion superconductor UPd 2Al 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 cotunneling 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 5 f electrons. This shows that while the hybridization gap opening is not directly associated with the antiferromagnetic ordering, its visibility in the conductance ismore » greatly affected by the temperature-dependent magnetic excitations. Our findings are not only consistent with the 5 f dual-nature picture in the literature but also shed new light on the interplay between the itinerant and localized electrons in UPd 2Al 3 .« less
Authors:
 [1] ;  [2] ;  [2] ;  [2] ;  [3] ; ORCiD logo [3] ; ORCiD logo [3] ; ORCiD logo [3] ;  [2]
  1. Illinois Wesleyan Univ., Bloomington, IL (United States); Univ. of Illinois, Urbana-Champaign, IL (United States). Dept. of Physics and Materials Research Lab.
  2. Univ. of Illinois, Urbana-Champaign, IL (United States). Dept. of Physics and Materials Research Lab.
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
LA-UR-16-28194
Journal ID: ISSN 2469-9950; TRN: US1702655
Grant/Contract Number:
AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 95; Journal Issue: 16; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC). Basic Energy Sciences (BES) (SC-22); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1369187
Alternate Identifier(s):
OSTI ID: 1351928

Jaggi, N. K., Mehio, O., Dwyer, M., Greene, L. H., Baumbach, Ryan E., Tobash, Paul H., Bauer, Eric Dietzgen, Thompson, Joe David, and Park, W. K.. Hybridization gap and dual nature of the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy. United States: N. p., Web. doi:10.1103/PhysRevB.95.165123.
Jaggi, N. K., Mehio, O., Dwyer, M., Greene, L. H., Baumbach, Ryan E., Tobash, Paul H., Bauer, Eric Dietzgen, Thompson, Joe David, & Park, W. K.. Hybridization gap and dual nature of the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy. United States. doi:10.1103/PhysRevB.95.165123.
Jaggi, N. K., Mehio, O., Dwyer, M., Greene, L. H., Baumbach, Ryan E., Tobash, Paul H., Bauer, Eric Dietzgen, Thompson, Joe David, and Park, W. K.. 2017. "Hybridization gap and dual nature of the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy". United States. doi:10.1103/PhysRevB.95.165123. https://www.osti.gov/servlets/purl/1369187.
@article{osti_1369187,
title = {Hybridization gap and dual nature of the heavy-fermion compound UPd2Al3 via quasiparticle scattering spectroscopy},
author = {Jaggi, N. K. and Mehio, O. and Dwyer, M. and Greene, L. H. and Baumbach, Ryan E. and Tobash, Paul H. and Bauer, Eric Dietzgen and Thompson, Joe David and Park, W. K.},
abstractNote = {We present results from point-contact spectroscopy of the antiferromagnetic heavy-fermion superconductor UPd2Al3 : 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 cotunneling 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 5 f 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 5 f dual-nature picture in the literature but also shed new light on the interplay between the itinerant and localized electrons in UPd2Al3 .},
doi = {10.1103/PhysRevB.95.165123},
journal = {Physical Review B},
number = 16,
volume = 95,
place = {United States},
year = {2017},
month = {4}
}