Evidence for a Novel State of Superconductivity in Noncentrosymmetric<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow><mml:mi mathvariant="normal">C</mml:mi><mml:mi mathvariant="normal">e</mml:mi><mml:mi mathvariant="normal">P</mml:mi><mml:mi mathvariant="normal">t</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub><mml:mi mathvariant="normal">S</mml:mi><mml:mi mathvariant="normal">i</mml:mi></mml:math>: A<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" dis

Yogi, Mamoru; Kitaoka, Y.; Hashimoto, Shin; Yasuda, Takashi; Settai, Rikio; Matsuda, Tatsuma D.; Haga, Yoshinori; Ōnuki, Yoshichika; Rogl, P.; Bauer, E.

doi:10.1103/physrevlett.93.027003

Cited by 151 publications

(143 citation statements)

References 21 publications

Supporting

Mentioning

129

Contrasting

Order By: Relevance

“…Such a gap with line nodes is also suggested by measurements of the London penetration depth [8]. At first sight, those experimental results seem to be mutually contradicting, as the features of unconventional Cooper pairing (line nodes) and of conventional superconductivity (peak in T −1 1 due to the coherence effect) are implied at the same time by the temperature dependence of T −1 1 [8,13,14].In the present study, we demonstrate that these apparently conflicting behaviors can be reconciled by taking account of the mixing of the pairing channels with opposite parity, which naturally occurs in superconductors without inversion center. For this purpose, we consider a pairing model with a two-component order parameter consisting of spin-singlet and spin-triplet pairing components.…”

mentioning

confidence: 75%

mentioning

confidence: 82%

“…CePt 3 Si displays further intriguing properties. Recent nuclear magnetic resonance (NMR) experiments found an overall anomalous temperature dependence of the nuclear spin-lattice relaxation rate T −1 1 [8,13,14]. The behavior of T −1 1 shows a (Hebel-Slichter) peak just below the superconducting critical temperature T c , and simultaneously a T 3 dependence at low temperatures indicating line nodes in the quasiparticle gap.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Nuclear magnetic relaxation rate in a noncentrosymmetric superconductor

et al. 2006

View full text Add to dashboard Cite

For a noncentrosymmetric superconductor such as CePt3Si, we consider a Cooper pairing model with a two-component order parameter composed of spin-singlet and spin-triplet pairing components. We demonstrate that such a model on a qualitative level accounts for experimentally observed features of the temperature dependence of the nuclear spin-lattice relaxation rate T −1 1 , namely a peak just below Tc and a line-node gap behavior at low temperatures.Inversion symmetry is one of the key points for the formation of Cooper pairs in superconductors. Unusual properties arise in superconductors whose crystal structure does not possess an inversion center (e.g., Refs. [1,2,3,4,5], and references therein). The recent discovery of superconductivity in the noncentrosymmetric heavy Fermion compound CePt 3 Si has initiated much interest, as experimental data revealed various intriguing features [6,7,8]. The essential element in modelling noncentrosymmetric systems is the presence of antisymmetric spin-orbit coupling [9,10]. One of the characteristic features in the superconducting phase is the mixing of the spin-singlet and spin-triplet Cooper pairing channels which are otherwise distinguished by parity [2]. This is likely responsible for the surprisingly high value of the upper critical field H c2 which exceeds the paramagnetic limit [3,6,8,11,12]. CePt 3 Si displays further intriguing properties. Recent nuclear magnetic resonance (NMR) experiments found an overall anomalous temperature dependence of the nuclear spin-lattice relaxation rate T −1 1 [8,13,14]. The behavior of T −1 1 shows a (Hebel-Slichter) peak just below the superconducting critical temperature T c , and simultaneously a T 3 dependence at low temperatures indicating line nodes in the quasiparticle gap. Such a gap with line nodes is also suggested by measurements of the London penetration depth [8]. At first sight, those experimental results seem to be mutually contradicting, as the features of unconventional Cooper pairing (line nodes) and of conventional superconductivity (peak in T −1 1 due to the coherence effect) are implied at the same time by the temperature dependence of T −1 1 [8,13,14].In the present study, we demonstrate that these apparently conflicting behaviors can be reconciled by taking account of the mixing of the pairing channels with opposite parity, which naturally occurs in superconductors without inversion center. For this purpose, we consider a pairing model with a two-component order parameter consisting of spin-singlet and spin-triplet pairing components. Such a model contains the necessary ingredients to account for the observed features of T −1 1 , i.e., the linenode behavior at low temperatures and the coherence effect just below T c . At the same time, the pairing model would also explain the temperature dependence of the London penetration depth qualitatively and be consistent with earlier studies of H c2 [3,15].We base our analysis on a Hamiltonian considered in Ref. [3], in which the lack of inversion symmetry is incorporated ...

show abstract

mentioning

confidence: 75%

mentioning

confidence: 82%

mentioning

confidence: 99%

See 1 more Smart Citation

Nuclear magnetic relaxation rate in a noncentrosymmetric superconductor

et al. 2006

View full text Add to dashboard Cite

show abstract

“…On the other hand, a small Hebel-Slichter peak just below T c observed in Ref. [22] was not found in other experiments [23]. Theoretically, the standard analysis of the NMR relaxation rate in superconductors, see e.g.…”

mentioning

confidence: 94%

“…The measurements of the NMR relaxation rate in CePt 3 Si [22] indicate the likely presence of line nodes. On the other hand, a small Hebel-Slichter peak just below T c observed in Ref.…”

mentioning

confidence: 99%

NMR relaxation rate in noncentrosymmetric superconductors

Samokhin

2005

Phys. Rev. B

View full text Add to dashboard Cite

The spin-lattice relaxation rate of nuclear magnetic resonance in a clean superconductor without inversion center is calculated for arbitrary pairing symmetry and band structure, in the presence of strong spin-orbit coupling.PACS numbers: 74.25. Nf, 74.20.Rp, 74.70.Tx Most superconducting materials have an inversion center in their crystal lattices. Among a few exceptions are the heavy-fermion compounds CePt 3 Si [1] and UIr [2]. The peculiar feature of superconductivity without inversion center is that there are fewer pairing channels available than in a centrosymmetric crystal, because the spin degeneracy of the bands is lifted in the presence of strong spin-orbit coupling [3,4]. Other properties of non-centrosymmetric superconductors studied recently include paramagnetic limit and Knight shift [5,6,7,8,9,10,11], helical superconducting phases [12,13,14], and magnetoelectric phenomena [15,16,17]. The determination of the pairing symmetry however presents a considerable challenge. Although there are strong indications that the gap in CePt 3 Si has lines of nodes, the decisive proof, including the determination of the nodal locations, is still lacking.A powerful probe of the quasiparticle properties in superconductors is the spin-lattice relaxation rate T −1 1 of nuclear magnetic resonance (NMR). The presence of the coherence, or Hebel-Slichter, peak in T −1 1 below the critical temperature [18] provided an early strong support for the Bardeen-Cooper-Schrieffer theory of superconductivity [19]. More recently, the power-law behavior of the relaxation rate at low temperatures commonly observed in heavy-fermion compounds, see e.g. Ref.[20], has been used as an argument in favor of the existence of gapless excitations in those materials. Indeed, if there are line (point) nodes in the gap, thenThe measurements of the NMR relaxation rate in CePt 3 Si [22] indicate the likely presence of line nodes. On the other hand, a small Hebel-Slichter peak just below T c observed in Ref. [22] was not found in other experiments [23]. Theoretically, the standard analysis of the NMR relaxation rate in superconductors, see e.g. Ref.[19], is not directly applicable in the noncentrosymmetric case because of a complicated spin structure of the non-degenerate bands. The purpose of the present Rapid Communication is to calculate T −1 1 in a non-centrosymmetric superconductor with arbitrary pairing symmetry. Our analysis does not rely on any specific model for the band structure, the only assumption being that the bands are well split due to strong spinorbit coupling, which is the case for CePt 3 Si [3]. In these circumstances, it is convenient to use the exact band representation of the order parameter introduced in Ref.[3], see also Ref. [4], in which the possibility of superconducting states with lines of nodes at high-symmetry locations appears naturally. In the alternative approach developed in Ref.[8], the spin-orbit coupling is introduced using the Rashba model, and the order parameter becomes a mixture of spin-singlet and spin-t...

show abstract

Ce-Pt-Si (Cerium - Platinum - Silicon)

Noble Metal Systems. Selected Systems From Ag-Al-Zn to Rh-Ru-Sc

View full text Add to dashboard Cite

Evidence for a Novel State of Superconductivity in NoncentrosymmetricCePt3Si: A

Cited by 151 publications

References 21 publications

Nuclear magnetic relaxation rate in a noncentrosymmetric superconductor

Nuclear magnetic relaxation rate in a noncentrosymmetric superconductor

NMR relaxation rate in noncentrosymmetric superconductors

Ce-Pt-Si (Cerium - Platinum - Silicon)

Contact Info

Product

Resources

About