Evidence for a Magnetically Driven SuperconductingQPhase ofCeCoIn5

Abstract

We have studied the magnetic order inside the superconducting phase of CeCoIn5 for fields along the [1 0 0] crystallographic direction using neutron diffraction. We find a spin-density wave order with an incommensurate modulation Q=(q,q,1/2) and q=0.45(1), which within our experimental uncertainty is indistinguishable from the spin-density wave found for fields applied along [1 -1 0]. The magnetic order is thus modulated along the lines of nodes of the d{x{2}-y{2}} superconducting order parameter, suggesting that it is driven by the electron nesting along the superconducting line nodes. We postulate that the onset of magnetic order leads to reconstruction of the superconducting gap function and a magnetically induced pair density wave.

Field-Induced Quantum Critical Point and Nodal Superconductivity in the Heavy-Fermion SuperconductorCe2PdIn8

“…More recently, NMR, neutron scattering, and muon spin rotation ( SR) experiments have provided clear evidence for a field-induced magnetism in this LTHF part of the phase diagram [16][17][18][19][20][21]. It was identified as a spin-density wave (SDW) order with an incommensurate modulation Q ¼ ð0:44; 0:44; 0:5Þ.…”

“…The novel FFLO state with broken spatial symmetry was predicted in the 1960s [13,14], but it has never been experimentally verified before. The possible FFLO state at the low-temperaturehigh-field (LTHF) corner of the H À T phase diagram of CeCoIn 5 has stimulated extensive studies [15].More recently, NMR, neutron scattering, and muon spin rotation ( SR) experiments have provided clear evidence for a field-induced magnetism in this LTHF part of the phase diagram [16][17][18][19][20][21]. It was identified as a spin-density wave (SDW) order with an incommensurate modulation Q ¼ ð0:44; 0:44; 0:5Þ.…”

“…Such a phase diagram is very similar to that of CeCoIn 5 [7,8], showing that there is also a field-induced QCP at H c2 . To clarify whether it is an AF QCP, more experiments such as NMR, neutron scattering, and SR are needed to detect the magnetic order below and above H c2 , as have been done with CeCoIn 5 [16][17][18][19][20][21].…”

Anomalous Upper Critical Field inCeCoIn5/YbCoIn5Superlattices with a Rashba-Type Heavy Fermion Interface

“…In the superlattice, the electronic structure becomes two-dimensional, which is expected to stabilize the FFLO phase [8]. Moreover, the three-dimensional magnetic order [12][13][14][15], which is responsible for the perplexing situation in the bulk sample, is expected to be strongly suppressed [4] due to negligibly small RKKY interaction between the adjacent CeCoIn 5 block layers through the YbCoIn 5 spacer. Furthermore, the importance of local inversion symmetry at the interface between CeCoIn 5 and YbCoIn 5 in the superlattice has recently been suggested to play a decisive role in superconducting properties, in particular when the thickness of CeCoIn 5 is only a few unit cells thick [16].…”

Fermi gas with attractive potential and spinS=32in a one-dimensional trap: Response functions for superfluidity and FFLO signatures

“…1,21 The crossover from three-dimensional (FFLO phase) to onedimensional (mixed phase) behavior is addressed in [47], where the phase diagram for a weakly interacting array of tubes is calculated. FFLO related phases have been observed in the strongly anisotropic heavy electron compound 48,49 CeCoIn 5 (the interpretation is still controversial 50 ) and in the quasi-two-dimensional organic compounds λ-(BETS) 2 FeCl 4 and (TMTSF) 2 ClO 4 . 51,52 Motivated by the work of K. Yang 21 in this paper we explore the possible formation of FFLO states in the mixed phases of quasi-one-dimensional systems with particles of spin S larger than 1/2.…”