Well-Defined Crystal Field Splitting Schemes and Non-Kramers Doublet Ground States of f Electrons in PrT2Zn20 (T = Ir, Rh, and Ru)

Iwasa, Kazuaki; Kobayashi, Hiroki; Onimaru, Takahiro; Matsumoto, Keisuke; Nagasawa, Naohiro; Takabatake, Toshiro; Ohira‐Kawamura, Seiko; Kikuchi, Tatsuya; Inamura, Yasuhiro; Nakajima, Kenji

doi:10.7566/jpsj.82.043707

Cited by 61 publications

(44 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PrIr 2 Zn 20 exhibits Curie-Weiss behavior for T > 30 K in magnetic susceptibility χ(T ) measurements with µ e f f 3.49(2) µ B /Pr (associated with paramagnetic Pr 3+ ions) [381,382]; however, analysis of χ(T ) data at low temperature and of a Schottky anomaly in specific heat data provided compelling evidence that is consistent with a Γ 3 nonmagnetic Kramers doublet ground state in PrIr 2 Zn 20 [382]. Inelastic neutron scattering measurements later confirmed this hypothesis, obtaining a Γ 3 (Γ 4 ) ground state (first excited state) split by ∼30 K [383]. The measured crystal-field excitations are very clear, indicating there are well-localized 4 f electron states that have not been broadened by correlation effects as typically occurs in Kondo systems [383].…”

Section: Superconductivity In Prt 2 X 20 Compoundsmentioning

confidence: 59%

Unconventional superconductivity in heavy-fermion compounds

White

Thompson

Maple

2015

Physica C: Superconductivity and its Applications

126

View full text Add to dashboard Cite

Over the past 35 years, research on unconventional superconductivity in heavy-fermion systems has evolved from the surprising observations of unprecedented superconducting properties in compounds that convention dictated should not superconduct at all to performing explorations of rich phase spaces in which the delicate interplay between competing ground states appears to support emergent superconducting states. In this article, we review the current understanding of superconductivity in heavy-fermion compounds and identify a set of characteristics that is common to their unconventional superconducting states. These core properties are compared with those of other classes of unconventional superconductors such as the cuprates and iron-based superconductors. We conclude by speculating on the prospects for future research in this field and how new advances might contribute towards resolving the long-standing mystery of how unconventional superconductivity works.

show abstract

Section: Superconductivity In Prt 2 X 20 Compoundsmentioning

confidence: 59%

Unconventional superconductivity in heavy-fermion compounds

White

Thompson

Maple

2015

Physica C: Superconductivity and its Applications

126

View full text Add to dashboard Cite

show abstract

“…It is known that the ground state is a non-Kramers doublet with E(Γ 3 ) representation. 21) Its basis states are…”

Section: Non-kramers Doublet For Pr Ionmentioning

confidence: 99%

“…Since the transition temperatures of the ordered phases are much lower than the energy scales of the CEF excited states, 21) it is justified to use an effective classical model constructed in terms of the non-Kramers doublet CEF ground states alone. In addition to antiferro quadrupole orders, ferro quadrupole and octupole orders are other possibilities of symmetry breaking, but we will not examine them in this paper.…”

Section: Introductionmentioning

confidence: 99%

Classical Monte Carlo Study for Antiferro Quadrupole Orders in a Diamond Lattice

Hattori

Tsunetsugu

2016

J. Phys. Soc. Jpn.

View full text Add to dashboard Cite

We investigate antiferro quadrupole orders in a diamond lattice under magnetic fields by Monte Carlo simulations for two types of classical effective models. One is an XY model with Z3 anisotropy, and the other is a two-component φ 4 model with a third-order anisotropy. We confirm that the universality class of the zero-field transition is that for the three-dimensional XY model. Magnetic field corresponds to a Z3 field in the effective model, and under this field, we find that collinear and canted antiferro-quadrupole orders compete. Each phase is characterized by symmetry breaking in the sector of (sublattice Z2)⊗(reflection Z2 for the order parameter). When Z3 anisotropy and magnetic field vary, it turns out that this system is a good playground for various multicritical points; bicritical and tetracritical points emerge in a finite field. Another important finding is about the scaling of parasitic ferro quadrupole order at the zero-field critical point. This is the secondary order parameter induced by the primary antiferro order, and its critical exponent β ′ =0.815 clearly differs from the expected value that is twice the value for the primary order parameter. The corresponding correlation length exponent is also different, ν ′ =0.597(12). We also discuss relation of the present effective quadrupole models with the 3-state Potts model as well as implication to undertanding of orbital orders in Pr-based 1-2-20 compounds.

show abstract

“…The analysis of these data indicates a nonmagnetic doublet ground state of the Pr 3+ ion [9,10]. Furthermore, in inelastic neutron scattering experiments, magnetic excitations from the doublet ground state were observed [8]. The analysis of the intensity of the excitation peaks suggested that the CEF ground state of Pr 3+ in PrRh 2 Zn 20 is a nonmagnetic Γ 23 doublet in the cubic T point group.…”

Section: Introductionmentioning

confidence: 91%

“…Because the point group of the Pr site is the cubic T d , the crystalline electric field (CEF) ground state could be a nonmagnetic doublet with the quadrupolar degrees of freedom [6]. In fact, doublet ground states of Pr 3+ in PrT 2 Zn 20 (T = Rh and Ir) have been confirmed by ultrasonic and inelastic neutron scattering measurements [7,8]. The compounds with T = Rh and Ir undergo AFQ orders at T Q = 0.06 and 0.11 K and superconducting transitions at T c = 0.06 and 0.05 K, respectively [6,9].…”

Section: Introductionmentioning

confidence: 98%

Suppression of Superconductivity in PrRh₂Zn₂₀by the Substitution of Co for Rh

Shimada

Nagasawa

Onimaru

et al. 2014

Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013)

Self Cite

View full text Add to dashboard Cite

Electrical resistivity ρ, magnetic susceptibility χ and specific heat C of Pr(Rh 1-x Co x ) 2 Zn 20 for 0 ≤ x ≤ 0.89 were measured to study the mechanism of simultaneous superconducting and antiferroquadrupolar (AFQ) transitions at T c = T Q = 0.06 K in PrRh 2 Zn 20 . A broad peak in the magnetic specific heat C m (T) at around 13 K is reproduced as a Schottky peak by a doublet-triplet two-levels model. However, another broad peak in C m (T) at 1 -3 K indicates splitting of the doublet state by a slight distortion of Zn cages due to the Co substitution. As a consequence of the splitting, the quadrupolar degrees of freedom must be quenched. With increasing x, T c = 0.06 K for x = 0 is suppressed below 0.04 K for x ≥ 0.10. The suppression of T c suggests possible interplay between the superconductivity and the quadrupolar degrees of freedom.

show abstract

Well-Defined Crystal Field Splitting Schemes and Non-Kramers Doublet Ground States of f Electrons in PrT₂Zn₂₀ (T = Ir, Rh, and Ru)

Cited by 61 publications

References 32 publications

Unconventional superconductivity in heavy-fermion compounds

Unconventional superconductivity in heavy-fermion compounds

Classical Monte Carlo Study for Antiferro Quadrupole Orders in a Diamond Lattice

Suppression of Superconductivity in PrRh₂Zn₂₀by the Substitution of Co for Rh

Contact Info

Product

Resources

About

Well-Defined Crystal Field Splitting Schemes and Non-Kramers Doublet Ground States of f Electrons in PrT2Zn20 (T = Ir, Rh, and Ru)

Cited by 61 publications

References 32 publications

Unconventional superconductivity in heavy-fermion compounds

Unconventional superconductivity in heavy-fermion compounds

Classical Monte Carlo Study for Antiferro Quadrupole Orders in a Diamond Lattice

Suppression of Superconductivity in PrRh2Zn20by the Substitution of Co for Rh

Contact Info

Product

Resources

About

Well-Defined Crystal Field Splitting Schemes and Non-Kramers Doublet Ground States of f Electrons in PrT₂Zn₂₀ (T = Ir, Rh, and Ru)

Suppression of Superconductivity in PrRh₂Zn₂₀by the Substitution of Co for Rh