Magnetic excitations in iron chalcogenide superconductors

Kotegawa, Hisashi; Fujita, M.

doi:10.1088/1468-6996/13/5/054302

Cited by 18 publications

(14 citation statements)

References 83 publications

(110 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This scenario matches with the experimental [46][47][48] and theoretical [49] findings that in FeTe the Fe moments align according to a magnetic wave vector (π ,0), in contrast with the AFM order along the nesting wave vector (π ,π ) of 1111 and 122 parent compounds. While the (π ,π ) spin fluctuations couple with carriers [50,51], (π ,0) spin fluctuations are not expected to, because they do not match any nesting wave vector [52,53]. This is observed in Fe 1+x Te 0.7 Se 0.3 superconducting samples where with increasing the interstitial iron concentration (x), (π ,π ) spin fluctuations disappear in favor of (π ,0) spin fluctuations and superconductivity disappears [54].We predict that, in principle, also FeTe devoided of interstitial iron should exhibit magnon drag Seebeck contribution.…”

Section: Data Analysis and Discussionmentioning

confidence: 99%

Magneto-Seebeck effect inRFeAsO(R=rareearth) compounds: Probing the magnon drag scenario

et al. 2014

View full text Add to dashboard Cite

We investigate the Seebeck effect in RFeAsO (R = rare earth) compounds as a function of temperature and magnetic field up to 30 T. The Seebeck curves are characterized by a broad negative bump around 50 K, which is sample dependent and strongly enhanced by the application of a magnetic field. A model for the temperature and field dependence of the magnon drag contribution to the Seebeck effect by antiferromagnetic (AFM) spin fluctuation is developed. It accounts for the magnitude and scaling properties of such bump feature in our experimental data in LaFeAsO. This analysis accounts for the apparent inconsistency of literature Seebeck effect data on these compounds and has the potential to extract precious information on the coupling between electrons and AFM spin fluctuations in these parent compound systems, with implications on the pairing mechanism of the related superconducting compounds.

show abstract

Section: Data Analysis and Discussionmentioning

confidence: 99%

Magneto-Seebeck effect inRFeAsO(R=rareearth) compounds: Probing the magnon drag scenario

et al. 2014

View full text Add to dashboard Cite

show abstract

“…In FeSe, the absence of long-range magnetic order despite the presence of nematic order [123] is striking and resulted in a large interest [58] in this purely nematic state and its interrelation with superconductivity. Given that strong magnetic fluctuations were observed at ambient pressure, [124][125][126][127][128][129] the "sought-for" magnetically ordered ground state was found to be stabilized in FeSe by the application of modest hydrostatic pressure, p ≳ 0.9 GPa, as first demonstrated by muon spin resonance ( SR) measurements under pressure. [62] This observation initiated ideas that the phase diagram of FeSe might depict features which are compatible with the universal phase diagram of iron-based superconductors [130,131] and therefore might still be consistent with a magnetically driven mechanism for nematicity and superconductivity.…”

Section: Phase Diagram Of Fese Under Hydrostatic Pressurementioning

confidence: 94%

“…Despite the absence of long-range magnetic order at ambient pressure, strong magnetic fluctuations of both stripe-type and Néel-type were detected. [124][125][126][127][128][129] Upon cooling through T s at ambient pressure, the spectral weight of the magnetic fluctuations is shifted toward lower energies and toward stripe type order. Since NMR measurements revealed that magnetic fluctuations become only strongly enhanced below T s , it was suggested that orbital order is the driver of nematicity at ambient pressure.…”

Section: Phase Diagram Of Fese Under Hydrostatic Pressurementioning

confidence: 99%

Hydrostatic and Uniaxial Pressure Tuning of Iron‐Based Superconductors: Insights into Superconductivity, Magnetism, Nematicity, and Collapsed Tetragonal Transitions

Gati

Bud’ko

et al. 2020

Annalen der Physik

View full text Add to dashboard Cite

Iron-based superconductors are well-known for their intriguing phase diagrams, which manifest a complex interplay of electronic, magnetic, and structural degrees of freedom. Among the phase transitions observed are superconducting, magnetic, and several types of structural transitions, including a tetragonal-to-orthorhombic and a collapsed-tetragonal transition. In particular, the widely observed tetragonal-to-orthorhombic transition is believed to be a result of an electronic order that is coupled to the crystalline lattice and is, thus, referred to as nematic transition. Nematicity is therefore a prominent feature of these materials, which signals the importance of the coupling of electronic and lattice properties. Correspondingly, these systems are particularly susceptible to tuning via pressure (hydrostatic, uniaxial, or some combination). Efforts to probe the phase diagrams of pressure-tuned iron-based superconductors are reviewed with a strong focus on recent insights into the phase diagrams of several members of this material class under hydrostatic pressure. These studies on FeSe, Ba(Fe 1−x Co x) 2 As 2 , Ca(Fe 1−x Co x) 2 As 2 , and CaK(Fe 1−x Ni x) 4 As 4 are, to a significant extent, made possible by advances of what measurements can be adapted to their use under differing pressure environments. The potential impact of these tools for the study of the wider class of strongly correlated electron systems is pointed out.

show abstract

“…Hints to the microscopic origins of magnetic correlations in FeSe can be found in the complex temperature and momentum dependence of magnetic fluctuations, and its imprints on the nematic state and superconductivity; see Section 3.3.5 below. Experimentally, these correlations have been studied using NMR and inelastic neutron scattering experiments [144,[151][152][153][154][155][156], with the latter summarized in Figure 7. In the spin nematic scenario, these fluctuations are argued to drive the nematic order, eventually leading to a divergence of the nematic susceptibility.…”

Section: Spin Fluctuations In Normal Statementioning

confidence: 99%

On the Remarkable Superconductivity of FeSe and Its Close Cousins

2020

View full text Add to dashboard Cite

Emergent electronic phenomena in iron-based superconductors have been at the forefront of condensed matter physics for more than a decade. Much has been learned about the origins and intertwined roles of ordered phases, including nematicity, magnetism, and superconductivity, in this fascinating class of materials. In recent years, focus has been centered on the peculiar and highly unusual properties of FeSe and its close cousins. This family of materials has attracted considerable attention due to the discovery of unexpected superconducting gap structures, a wide range of superconducting critical temperatures, and evidence for nontrivial band topology, including associated spin-helical surface states and vortex-induced Majorana bound states. Here, we review superconductivity in iron chalcogenide superconductors, including bulk FeSe, doped bulk FeSe, FeTe1−xSex, intercalated FeSe materials, and monolayer FeSe and FeTe1−xSex on SrTiO3. We focus on the superconducting properties, including a survey of the relevant experimental studies, and a discussion of the different proposed theoretical pairing scenarios. In the last part of the paper, we review the growing recent evidence for nontrivial topological effects in FeSe-related materials, focusing again on interesting implications for superconductivity.

show abstract

Magnetic excitations in iron chalcogenide superconductors

Abstract: Nuclear magnetic resonance and neutron scattering experiments in iron chalcogenide superconductors are reviewed

Cited by 18 publications

References 83 publications

Magneto-Seebeck effect inRFeAsO(R=rareearth) compounds: Probing the magnon drag scenario

Magneto-Seebeck effect inRFeAsO(R=rareearth) compounds: Probing the magnon drag scenario

Hydrostatic and Uniaxial Pressure Tuning of Iron‐Based Superconductors: Insights into Superconductivity, Magnetism, Nematicity, and Collapsed Tetragonal Transitions

On the Remarkable Superconductivity of FeSe and Its Close Cousins

Contact Info

Product

Resources

About