Superconductivity in the heavy fermion system PrOs₄Sb₁₂

Abu Alrub, Tayseer Rafe (2008) Superconductivity in the heavy fermion system PrOs₄Sb₁₂. Doctoral (PhD) thesis, Memorial University of Newfoundland.

[img] [English] PDF - Accepted Version
Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.

Download (6MB)


Superconductivity was observed in the Pr-filled skutterudite heavy fermion system PrOs₄Sb₁₂in 2002. Symmetry considerations, based on the Landau theory of second order phase transitions, were used to derive all possible superconducting states in this material. It was found that a three-component order parameter that belongs to the Tu irreducible representation of the tetrahedral point group Th best describes superconductivity in PrOs₄Sb₁₂. Two different superconducting phases have been observed in PrOs₄Sb₁₂; the lower temperature B phase occupies the bulk of the phase diagram, while the higher temperature A phase is found in a narrow region below Hc2 , and possibly does not exist at all. The proposed gap function in the A phase is unitary and has two point nodes in the [00 ± 1] directions. In the B phase, the proposed gap function is nonunitary and the lower branch has four point nodes in the [±α,0,±β] directions. Hence, thermodynamic and transport properties of a nonunitary superconducting state are analyzed. It is shown that the conductivity tensor has inequivalent diagonal components due to the off-axis nodal positions of the B phase. Moreover, nonuniversal conductivities (impurity scattering dependent) have been obtained. A semi-classical approach based on the Doppler shift of the quasiparticle energy is used to calculate the oscillatory past of the magnetic field-angle dependent density of states and thermal conductivity. All possible point node configurations for superconducting phases of a tetrahedral superconductor are considered.

Item Type: Thesis (Doctoral (PhD))
Item ID: 8925
Additional Information: Includes bibliographical references (leaves 101-110)
Department(s): Science, Faculty of > Physics and Physical Oceanography
Date: 2008
Date Type: Submission
Library of Congress Subject Heading: Fermions--Thermal conductivity; Group theory; Superconductivity

Actions (login required)

View Item View Item


Downloads per month over the past year

View more statistics