Spin excitations in a single La2CuO4 layer

Dean, M. P. M.; Springell, R.; Monney, Claude; Zhou, Kejin; Pereiro, J.; Božović, I.; Piazza, B. Dalla; Rønnow, Henrik M.; Morenzoni, E.; Brink, Jeroen van den; Schmitt, Thorsten; Hill, J. P.

doi:10.1038/nmat3409

Cited by 139 publications

(156 citation statements)

References 30 publications

Supporting

Mentioning

139

Contrasting

Order By: Relevance

“…This class of experiments is particularly valuable because it probes the set of collective and local excitations that are supposedly involved with the basic mechanisms of high temperature superconductivity. In particular, high resolution RIXS at Cu−L 3 edge has been used to measure the magnon dispersion in undoped insulating cuprates [3][4][5][6] , and damped spin excitations (paramagnons) in hole-doped (h-doped) cuprates. It has thus been shown that paramagnons persist throughout the phase diagram, from superconducting underand optimally-doped [7][8][9] to non-superconducting highly-overdoped 10 samples.…”

Section: Introductionmentioning

confidence: 99%

Spin and charge excitations in artificial hole- and electron-doped infinite layer cuprate superconductors

et al. 2017

View full text Add to dashboard Cite

The asymmetry between electron-and hole-doping in high critical-temperature superconducting (HTS) cuprates is key information for the understanding of Cooper pairs formation mechanisms.Despite intensive studies on different cuprates, a comprehensive description of related magnetic and charge excitations is still fragmentary. In the present work, artificial cuprates were used to cover the entire phase diagram within the same HTS family. In particular, Cu L 3 -edge resonant inelastic x-ray scattering (RIXS) measurements were performed on artificial n-and p-type infinite layers (IL) epitaxial films. Beside several similarities, RIXS spectra show noticeable differences in the evolution, with doping level, of magnetic and charge intensity and damping. Compatible trends can be found in spectra measured on bulk cuprates, as well as in theoretical calculations of the spin dynamical structure factor S(q, ω). The findings give a deeper insight about the evolution of collective excitations across the cuprate phase diagram, and on underlying general features, only connected to the doping type. Moreover they pave the way to the exploration of general properties of HTS physics over a broad range of conditions, by means of artificial compounds not constrained by the thermodynamic limitations governing the chemical stability of bulk materials.

show abstract

Section: Introductionmentioning

confidence: 99%

Spin and charge excitations in artificial hole- and electron-doped infinite layer cuprate superconductors

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The physical novelty of this material is demonstrated by the emergence of ferromagnetic order, which is rare in pure cuprates or iridates (the closely related materials Sr 3 CuPtO 6 and Sr 3 ZnIrO 6 are antiferromagnetic) and was used to synthesize random quantum spin chain paramagnetism in Sr 3 CuIr 1−x Pt x O 6 [16,17]. There is to date no microscopic understanding of this unique phenomenon of ferromagnetism.Here, we use Ir L 3 edge resonant inelastic x-ray scattering (RIXS) [5,14,18,19] to reveal a large gap magnetic excitation spectrum in Sr 3 CuIrO 6 and show that it is well described by an effective S = 1/2 ferromagnetic Heisenberg model with an Ising-like exchange anisotropy. We present a microscopic derivation of this model and find that the arrangement of alternating isospins and real spins on the edge-sharing Ir 4+ O 6 -Cu 2+ O 4 chain leads to an unexpected effect, namely, that the ferromagnetic anisotropy arises from the antiferromagnetic superexchange.…”

mentioning

confidence: 99%

“…Here, we use Ir L 3 edge resonant inelastic x-ray scattering (RIXS) [5,14,18,19] to reveal a large gap magnetic excitation spectrum in Sr 3 CuIrO 6 and show that it is well described by an effective S = 1/2 ferromagnetic Heisenberg model with an Ising-like exchange anisotropy. We present a microscopic derivation of this model and find that the arrangement of alternating isospins and real spins on the edge-sharing Ir 4+ O 6 -Cu 2+ O 4 chain leads to an unexpected effect, namely, that the ferromagnetic anisotropy arises from the antiferromagnetic superexchange.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Ferromagnetic Exchange Anisotropy from Antiferromagnetic Superexchange in the Mixed3d−5dTransition-Metal CompoundSr3CuIrO6

et al. 2013

Self Cite

View full text Add to dashboard Cite

We report a combined experimental and theoretical study of the unusual ferromagnetism in the one-dimensional copper-iridium oxide Sr3CuIrO6. Utilizing Ir L3 edge resonant inelastic x-ray scattering, we reveal a large gap magnetic excitation spectrum. We find that it is caused by an unusual exchange anisotropy generating mechanism, namely, strong ferromagnetic anisotropy arising from antiferromagnetic superexchange, driven by the alternating strong and weak spin-orbit coupling on the 5d Ir and 3d Cu magnetic ions, respectively. From symmetry consideration, this novel mechanism is generally present in systems with edge-sharing Cu 2+ O4 plaquettes and Ir 4+ O6 octahedra. Our results point to unusual magnetic behavior to be expected in mixed 3d − 5d transition-metal compounds via exchange pathways that are absent in pure 3d or 5d compounds. The interest in strongly correlated electronic systems has recently been extended from 3d transition-metal compounds (TMCs) to 5d compounds. Usually, the strength of electron correlation is characterized by the ratio of the local Coulomb repulsion to the electronic bandwidth. A large value of this ratio (∼ 8) is common in 3d TMCs such as superconducting cuprates [1]. Since 5d orbitals are more extended in space and host weaker Coulomb interactions than 3d orbitals, 5d TMCs are generally expected to be weakly correlated. However, it has been pointed out [2][3][4] that the relative weakness of the Coulomb interaction is offset by the strong spin-orbit coupling (SOC), which is typically ∼ 0.5 eV for 5d elements. This strong SOC leads to a significant splitting and narrowing of the electronic bands, and pushes 5d TMCs toward the strongly correlated regime. Indeed, the SOC-driven Mott metal-insulator transition was shown to exist in a variety of 5d iridium oxides [2][3][4][5][6][7][8][9][10][11][12][13][14]. An important consequence of this is the entanglement of the orbital and spin degrees of freedom in the resulting localized magnetic moments (termed "isospins"), which can lead to unusual superexchange pathways and to new physics, for example, the proposed spin-liquid state as encoded in the Kitaev model [15] in the honeycomb-lattice (Li,Na) 2 IrO 3 [7] and possible superconductivity in the square-lattice Sr 2 IrO 4 , which shows similar magnetic ordering and dynamics to the cuprates [5].The purpose of this Letter is to demonstrate that materials containing both 3d and 5d magnetic ions can host new physics absent in either pure 3d or pure 5d compounds-because of the unique combination of unusual exchange pathways and special geometries, a result of the strong SOC of the 5d electrons and the differing coordinations of the 3d and 5d sites. Such materials will offer new avenues to engineer exotic magnetic behavior. To demonstrate this, we have chosen to study the one-dimensional copper-iridium oxide Sr 3 CuIrO 6 , as a prototype for such mixed 3d − 5d systems. The crystal structure of this compound [ Fig. 1(a)] is reminiscent of both the superconducting cuprates and the iridiumbased M...

show abstract

“…Ck, 74.20.Rp Introduction In the past decade, resonant inelastic x-ray scattering (RIXS) [1,2] has made remarkable progress as a spectroscopic technique, establishing itself as an experimental probe of elementary spin [3][4][5][6][7][8], orbital [9,10], and lattice excitations [11]. In quite a number of cases, theoretical considerations have preceded and stimulated these experimental advances, prominent examples being the theoretical demonstration of the presence of strong single-magnon scattering channels in cuprates [12,13] and iridates [14].…”

mentioning

confidence: 99%

Resonant Inelastic X-Ray Scattering as a Probe of the Phase and Excitations of the Order Parameter of Superconductors

et al. 2013

View full text Add to dashboard Cite

The capability to probe the dispersion of elementary spin, charge, orbital, and lattice excitations has positioned resonant inelastic s-ray scattering (RIXS) at the forefront of photon science. Here we develop the scattering theory for RIXS on superconductors, calculating its momentum-dependent scattering amplitude. Considering superconductors with different pairing symmetries we show that the low-energy scattering is strongly affected by the superconducting gap and coherence factors. This establishes RIXS as a tool to disentangle pairing symmetries and to probe the elementary excitations of unconventional superconductors.PACS numbers: 78.70. Ck, 74.20.Rp Introduction In the past decade, resonant inelastic x-ray scattering (RIXS) [1,2] has made remarkable progress as a spectroscopic technique, establishing itself as an experimental probe of elementary spin [3][4][5][6][7][8], orbital [9,10], and lattice excitations [11]. In quite a number of cases, theoretical considerations have preceded and stimulated these experimental advances, prominent examples being the theoretical demonstration of the presence of strong single-magnon scattering channels in cuprates [12,13] and iridates [14]. Being a photonin/photon-out spectroscopy, both the energy ω and the momentum change q of the scattered photon are measured. As the energy and momentum lost by the photon are transferred to intrinsic excitations of the material under study, direct information on the dispersion of those excitations becomes available. The resonant character of the technique is due to the energy of the incident photon being chosen such that it coincides, and hence resonates, with an x-ray absorption edge of the system [1,2]. This year the energy resolution of RIXS has reached ∼30 meV in the hard x-ray regime [7], will reach 50 meV in the soft x-ray regime by building on present instrumentation [15] and is designed to reach 11 meV at the Cu L-edges at the NSLS-II presently under construction [16]. This brings the RIXS energy resolution well into the regime of the energy gap of cuprate superconductors, which stretches out to 119 meV for mercury-based high T c systems [17]. Consequently the fundamental question arises of how the superconducting (SC) state leaves its fingerprints in RIXS spectra -in particular whether and how RIXS is sensitive to the phase and amplitude of the SC gap and to quasiparticle excitations.Probing the order parameter in unconventional superconductors is generally the first step for an investigation of the pairing mechanism and of the character of the SC state. Compared to the available spectroscopic methods, such as scanning-tunneling spectroscopy (STS), photoemission spectroscopy, optical spectroscopy or inelastic neutron scattering, RIXS uniquely combines the advantages of bulk-sensitivity and availability of momentum resolution while at the same time requiring only small sample volumes. Here we show how the sensitivity of the RIXS process to the dynamical structure factor (DSF) of the electron spin and density in the SC state...

show abstract

Spin excitations in a single La2CuO4 layer

Cited by 139 publications

References 30 publications

Spin and charge excitations in artificial hole- and electron-doped infinite layer cuprate superconductors

Spin and charge excitations in artificial hole- and electron-doped infinite layer cuprate superconductors

Ferromagnetic Exchange Anisotropy from Antiferromagnetic Superexchange in the Mixed3d−5dTransition-Metal CompoundSr3CuIrO6

Resonant Inelastic X-Ray Scattering as a Probe of the Phase and Excitations of the Order Parameter of Superconductors

Contact Info

Product

Resources

About